cssi/SciSciGPT-SciSciNet huggingface dataset:
The Unique Strength of Diamond

The features of diamond that make it unique are: 1] its efficient tetrahedral structure which is stabilized by resonance of the bonding electrons among adjacent bonds; 2] the exceptionallly high ratios of its shear moduli to its bulk modulus; 3] the large gap between the top of its valence band and the bottom of its conduction band which makes dislocation mobility very low in it; 4] its high surface energy. Although diamond is nearly elastically Isotropic, the ratio of its C44 shear constant to its bulk modulus is 1.3 which is the highest measured value for this ratio. It is quite unusual for it to be greater than unity. This high shear stiffness appears to be associated with the bimodal distribution of electrons along the lengths of the C-C bonds. Also, for centrally directed interatomic forces, the ratio C44/C12is expected to be unity. But In diamond it is 4.6, indicating that the behavior of diamond cannot be described even approximately by pair-potentials. Because of its unique strength diamond can perform exceptionally in mechanical devices such as: pressure vessels, ultracentrifuges, springs, flywheels, and cutting (or drawing) tools.
Why are high-Mg# andesites widespread in the western Aleutians? A numerical model approach

High-Mg# andesites are thought to be derived from partial melting of subducting oceanic basalts. Slab thermal modeling has shown that this requires a young (
Efficient synthesis of benzobisazole terpolymers containing thiophene and fluorene

We report the synthesis and lumuminescence properties of three novel polymers composed of 9,9-dioctylfluorene and a donor–acceptor-donor (D–A-D) triad of a benzobisazole moiety sandwiched between two octylthiophenes. The requiste monomers, 2,6-bis(5-bromo-3-octylthiophen-2-yl)-benzobisazoles were obtained efficiently via the Lewis acid catalyzed cyclization of 2-bromo-3-octyl-5-(triethoxymethyl)thiophene and the corresponding diamino diols or dithiols. The polymers were synthesized in excellent yield by the Suzuki coupling reaction between the D–A-D benzobisazole monomers and 9,9-dioctylfluorene bisboronic acid. Alkyl side chains provided the polymers with solubility in common organic solvents, enabling characterization using gel permeation chromatography, 1H NMR, UV-Vis and fluorescence spectroscopy. The polymers have optical bandgaps of 2.43–2.63 eV and HOMO levels at −5.54 to −5.65 eV relative to vacuum as determined by UV visible and photoelectron spectroscopy respectively. Light-emitting diodes using blends of the copolymers in a poly(N-vinyl carbazole) matrix yielded blue-green emission with luminous efficiencies of 0.86 Cd/A at ∼505 nm. This efficient and high-yielding route is a promising approach for the synthesis of polymers containing benzobisazole moieties.
Optical Sensing of Cesium Using 1,3-Alternate Calix[4]-mono- and Di(anthrylmethyl)aza-crown-6

We have synthesized two derivatives of alkylanthracene covalently bonded to 1,3-alternate calix[4]aza-crown-6 at the nitrogen position to study the effect of alkali metal ion complexation on the emission properties of anthracene fluorophore. The mono- and dianthryl-substituted probes are weakly fluorescent because their emission is partially quenched by photoinduced electron transfer (PET) from the nitrogen lone pair to the excited singlet state of anthracene. Upon complexation of alkali metal ions (e.g. K 1 ,C s 1 ) by the crown moiety, the nitrogen lone pair can no longer participate in the PET process causing an enhancement in the emission of anthracene fluorophore (fluorescent turn on). The maximum fluorescence enhancement observed upon complexation of cesium ions by mono- and dianthryl-substituted calix[4]aza-crown-6 relative to the uncomplexed form was 8.5- and 11.6-fold, respectively.
Annealing Temperature and Substrate Effects on the Raman Spectra of Transferred CVD Graphene

This work explores the influence of the post-transfer anneal temperature and the substrate on transferred graphene and its Raman properties. Graphene grown by low pressure chemical vapor deposition on copper foils was transferred to SiO2/Si, fused silica, and silicon substrates via a process that involves coating the graphene with PMMA as a protective handling layer during the wet chemical etching of the copper and then placing the PMMA/graphene onto the substrate. The PMMA layer was then removed by heating in a hydrogen/argon atmosphere at temperatures ranging from 350 to 550 °C or by exposing the PMMA to heated acetone vapor/liquid. Raman spectroscopy measurements, taken before and after PMMA removal, reveal differences in the prominent Raman features, the G and G′ peaks, upon annealing. These changes include (1) a shift in the average G and G′ peak positions when comparing Raman spectra before and after PMMA removal and (2) a decrease in the G′:G peak intensity ratio (IG′/IG), which is typically used as a measure of the number of graphene layers. For both the as-transferred graphene and graphene removed by the heated acetone, the IG′/IG peak ratio was approximately 2, indicating single layer graphene. However, when the graphene was annealed at temperatures above 350 °C, the IG′/IG intensity ratio varied from 0.5 to 1.5. These changes in the Raman spectra are similar to those observed in exfoliated single layer graphene supported on SiO2/Si substrates and are indicative of graphene-substrate interaction effects that lead to hole doping of the graphene [1,2]. These trends were observed for graphene transferred to all three substrates, regardless of the substrate surface roughness and/or composition.
Resampling Techniques in the Analysis of Non-binormal ROC Data

The methods most commonly used for analyzing receiver operating characteristic (ROC) data incorporate "binormal" assumptions about the latent frequency distributions of test results. Although these assumptions have proved robust to a wide variety of actual frequency distributions, some data sets do not "fit" the binormal model. In such cases, resampling techniques such as the jackknife and the bootstrap provide versatile, distribution-indepen dent, and more appropriate methods for hypothesis testing. This article describes the ap plication of resampling techniques to ROC data for which the binormal assumptions are not appropriate, and suggests that the bootstrap may be especially helpful in determining con fidence intervals from small data samples. The widespread availability of ever-faster com puters has made resampling methods increasingly accessible and convenient tools for data analysis. Key words: receiver operating characteristic; ROC; resampling; jackknife; bootstrap; diagnostic testing; diagnostic...
Laplace transform application to a nontraditional dissolved oxygen model

A three-halves order biochemical oxygen demand (BOD) deoxygenation reaction is incorporated into a dissolved oxygen (DO) model to describe river water quality. The user is provided an alternative approach to the practice of using a first order BOD equation in river water quality models for DO. The new approach uses published BOD data sets of analyses of samples from rivers which are described best in the least squares sense by a three-halves order BOD reaction. The DO differential equation is solved by using the Laplace transform method. The time when the minimum DO concentration occurs is calculated numerically. The DO sag model is applied to examples to show the sensitivity of the model to changes in the three-halves order deoxygenation reaction rate constant and to changes in the BOD load.
Aggregation and the Nature of Price Expectations

Market liquidity requires differences of opinion among traders, but market behavior is often modeled using just one representative agent. This paper aggregates trading activity across many traders, at least one of which has rational expectations. Equilibrium price expectations depend on individual risk preferences and the expectations of all traders. Results indicate that positive feedback traders comprise a statistically significant minority of traders that has grown with the prevalence of commodity pools.
Effects of cell structure on a liquid crystal optical switch based on internal reflection

Using the Berreman 4x4 method we developed a simulation program to study the effects of cell structure parameters of a liquid crystal optical switch based on total internal reflection. The study shows that the liquid crystal may convert one polarization into another, because of its birefringence and thus degrades the performance of the switch. Good contrast ratios can be achieved by using alignment layers with weak anchoring strengths and appropriate thin cell gaps.
Heterogeneity in gap junction expression in astrocytes cultured from different brain regions.

Heterogeneity among astrocytes suggests that their role in the central nervous system is more complex than is commonly recognized. This paper describes just such a functional difference, comparing gap junctions in astrocytes derived from two brain regions. Astrocytes, both in situ and in culture, employ gap junctions as a means of intercellular communication. Recent evidence utilizing cultured rat cortical and striatal astrocytes has shown that these channels consist of subunits of connexin 43, the same protein as that composing cardiac gap junctions. Here we report that astrocytes cultured from neonatal rat hypothalamus contain a greater number of functional channels than astrocytes from the striatum, a difference reflected in both connexin 43 protein and mRNA. Specifically, in hypothalamic astrocytes the level of connexin 43 protein was approximately four times that found in comparable cultures from the striatum, as determined by immunoblotting. Complementary results from immunocytochemical experiments using an antibody specific for connexin 43 reveal significantly greater fluorescence in astrocytes cultured from the hypothalamus as compared to those from the striatum. Northern blot analysis showed that connexin 43 mRNA levels were also approximately 4-fold greater in the hypothalamic cultures, consistent with difference seen by immunoblotting. Finally, dye coupling studies using confluent cultures consistently showed that within 1 min Lucifer Yellow injected into striatal astrocytes spread to immediately surrounding cells while in hypothalamic astrocytes dye often spread to apparent third or fourth order neighbors within the same time period. Thus, the higher level of connexin 43 expression seen in hypothalamic astrocytes results in cells with greater numbers of functional channels. Interestingly, both the immunocytochemical and dye coupling experiments also revealed heterogeneity, among cells derived from each brain area, indicating that both region contain subpopulations of astrocytes. Taken together, our data show differences in gap junction expression, both within and between astrocytes derived from two brain regions. Further, this heterogeneity appears to derive from differences in either transcriptional regulation or in mRNA stability, and not from changes in the relative levels of phosphorylated forms of connexin 43. Thus, these data, which are consistent with light microscopic immunocytochemical studies in tissue sections of rat brain, predict that, in vivo, region-specific coupling subserves functional specialization within the central nervous system. © 1992 Wiley-Liss, Inc.
Information arbitrage across multi-lingual Wikipedia

The rapid globalization of Wikipedia is generating a parallel, multi-lingual corpus of unprecedented scale. Pages for the same topic in many different languages emerge both as a result of manual translation and independent development. Unfortunately, these pages may appear at different times, vary in size, scope, and quality. Furthermore, differential growth rates cause the conceptual mapping between articles in different languages to be both complex and dynamic. These disparities provide the opportunity for a powerful form of information arbitrage--leveraging articles in one or more languages to improve the content in another. Analyzing four large language domains (English, Spanish, French, and German), we present Ziggurat, an automated system for aligning Wikipedia infoboxes, creating new infoboxes as necessary, filling in missing information, and detecting discrepancies between parallel pages. Our method uses self-supervised learning and our experiments demonstrate the method's feasibility, even in the absence of dictionaries.
Optimal controller design for structural damage detection

The virtual passive control technique has recently been applied to structural damage detection, where the virtual passive controller only uses the existing control devices, and no additional physical elements are attached to the tested structure. One important task is to design passive controllers that can enhance the sensitivity of the identified parameters, such as natural frequencies, to structural damage. This paper presents a novel study of an optimal controller design for structural damage detection. We apply not only passive controllers but also low-order and fixed-structure controllers, such as PID controllers. In the optimal control design, the performance of structural damage detection is based on the application of a neural network technique, which uses the pattern of the correlation between the natural frequency changes of the tested system and the damaged system.
Beyond the Arab revolts: conceptualizing civil society in the Middle East and North Africa

How do we make sense of the potential role of civil society in the Middle East and North Africa (MENA) in bringing the region into a new era of reform and political participation? This article critically examines how the civil society landscape in the region has been conceptualized in the past and proposes a new typology of MENA civil society actors. I employ this typology in two cases – the revolutionary uprising in Egypt in 2011 and “evolutionary” long-term efforts to broaden the space for political participation in Lebanon. Comparing these two very different cases illustrates the utility of a typology of civil society actors (CSAs) that (a) emphasizes temporary coalitions between diverse actors; (b) highlights the both contentious and collaborative struggles through which political change actually happens; and (c) recognizes that different types of CSAs face different constraints and opportunities. I argue that employing such a typology can help structure comparison between disparate cases of civil soc...
Inhibition of KIT Tyrosine Kinase Activity: A Novel Molecular Approach to the Treatment of KIT-Positive Malignancies

PURPOSE: Activation of the KIT tyrosine kinase by somatic mutation has been documented in a number of human malignancies, including gastrointestinal stromal tumor (GIST), seminoma, acute myelogenous leukemia (AML), and mastocytosis. In addition, paracrine or autocrine activation of this kinase has been postulated in numerous other malignancies, including small-cell lung cancer and ovarian cancer. In this review, we discuss the rationale for and development of KIT tyrosine kinase inhibitors for the treatment of human malignancies. MATERIALS AND METHODS: Studies were identified through a MEDLINE search, review of bibliographies of relevant articles, and review of abstracts from national meetings. RESULTS: Four tyrosine kinase inhibitors that have activity against KIT are currently being used in clinical trials, and one, STI571, has recently been approved by the United States Food and Drug Administration for treating patients with chronic myelogenous leukemia. The role of KIT inhibitors in treating KIT-posit...
The Influence of Ron Paul: Loud Bang or Flash in the Pan?

The 2012 primary season has been one of the most volatile in recent memory, with the Republican Party struggling to settle on a candidate. The campaign has also vaulted some previously obscure politicians to national prominence, only to relegate them again to obscurity. Ron Paul has demonstrated perhaps the most dramatic transformation, from a lone voice who was once largely ignored to one of the last four candidates for the nomination, who has performed quite creditably in several primaries. In this article, I examine how much influence Paul is going to have in the short term, up to and including the Republican National Convention. I also examine how lasting his influence will be over the long term, and whether or not he will mount a third-party bid in 2012.
The Problem of Ideology in Biblical Studies

The issue of ideology is one which is still in need of discussion in biblical studies. In this article I will map the way that the various strains of social approaches to New Testament have started to address this issue, though often indirectly. I will then move to an explicit discussion of the issue making reference to the Marxist tradition focusing on Marx, Althusser and Žižek. I will argue that rather than the more traditional view which focuses on a non-ideological space like science, a better approach is one championed by Žižek which looks for gaps and cracks in the social world which then lend themselves to ideological criticism.
The Effect of Core Surface Morphology on Flake Attributes: Evidence from a Controlled Experiment

This paper presents the results of a controlled experiment which examined the relationship between core surface morphology and the flake attributes of length, thickness and mass. It was found that the relationship between platform thickness and flake mass is not influenced by core surface morphology, but that the relationship between platform thickness and the flake dimensions of flake length and thickness is significantly influenced. These results suggest that core surface morphology plays an important role in the conservation of raw material and the increased transportability of flake blanks and tools.
Predicted impacts of climate and land use change on surface ozone in the Houston, Texas, area

[1] This paper studies the effects of climate change under future A1B scenario and land use change on surface ozone (O3) in the greater Houston, Texas, area. We applied the Weather Research and Forecasting Model with Chemistry (WRF/Chem) to the Houston area for August of current (2001–2003) and future (2051–2053) years. The model was forced by downscaled 6-hourly Community Climate System Model (CCSM) version 3 outputs. High-resolution current year land use data from National Land Cover Database (NLCDF) and future year land use distribution based on projected population density for the Houston area were used in the WRF/Chem model coupled with an Urban Canopy Model (UCM). Our simulations show that there is generally a 2°C increase in near-surface temperature over much of the modeling domain due to future climate and land use changes. In the urban area, the effect of climate change alone accounts for an increase of 2.6 ppb in daily maximum 8-h O3 concentrations, and a 62% increase of urban land use area exerts more influence than does climate change. The combined effect of the two factors on O3 concentrations can be up to 6.2 ppb. The impacts of climate and land use change on O3 concentrations differ across the various areas of the domain. The increase in extreme O3 days can be up to 4–5 days in August, in which land use contributes to 2–3 days' increase. Additional sensitivity experiments show that the effect of future anthropogenic emissions change is on the same order of those induced by climate and land use change on extreme O3 days.
Self-phase tracked fiber-optical parametric sampling gate for 640-Gb/s OTDM de-multiplexing

We demonstrate an all-optical OTDM de-multiplexer with in-built phase-tracking capability using four-wave mixing and cross phase modulation in a single fiber device. Error-free performance was attained at 640 Gb/s even in the presence of a rapid temporal drift.
Reexamination of the structure of a laser-stabilized Si{111}1 x 1 surface.

The graphite-like model recently proposed by Jones and Holland for the structure of a laser-stabilized Si)111)1 x 1 surface is subjected to a new low-energy electron-diffraction (LEED) intensity analysis and compared to the relaxed-bulk model produced by earlier LEED analyses. Three different reliability factors applied to the normal-incidence data, and visual evaluation of non-normal-incidence data, discriminate unambiguously in favor of the relaxed-bulk model against the graphite-like model.
Effectiveness of DuPont Typar sheeting in controlling macrophyte regrowth after overwinter drawdown.

: A new polypropylene sheeting compound, DuPont Typar 3201 and 3301, was applied to the sediments of Country Lake (Portage Co., Ohio) in March 1978 after an overwinter drawdown, and regrowth of rooted macrophytes was compared to an adjacent control area in summer 1978. Regrowth was slight, and macrophyte biomass was at least 100X less than in controls. The sheeting material was permeable to gases and did not “balloon.” This material is recommended for use around docks, swimming areas, and boat mooring sites. Cost in 1978 was about $0.24/m2.
A globally stable linear attitude regulator

The problem considered in this paper is that of designing an attitude regulator for an arbitrary rigid body. The design criterion is that, in the presence of no disturbance torques on the body, the system should have only one equilibrium point, and this point should be asymptotically stable for arbitrary initial conditions. By use of Lyapunov techniques and an appropriate choice of state variables, it is shown that this criterion can be satisfied by employing a linear feedback law with constant coefficients.
Probing Kinetic Mechanisms of Protein Function and Folding with Time-Resolved Natural and Magnetic Chiroptical Spectroscopies

Recent and ongoing developments in time-resolved spectroscopy have made it possible to monitor circular dichroism, magnetic circular dichroism, optical rotatory dispersion, and magnetic optical rotatory dispersion with nanosecond time resolution. These techniques have been applied to determine structural changes associated with the function of several proteins as well as to determine the nature of early events in protein folding. These studies have required new approaches in triggering protein reactions as well as the development of time-resolved techniques for polarization spectroscopies with sufficient time resolution and sensitivity to probe protein structural changes.
Singularities and catastrophes in the dynamics of one-dimensional systems.

Dynamical correlation functions at low temperature for one-dimensional systems that involve the decay of a single elementary excitation into three others show logarithmic singularities at the frequency of the original excitation, as well as discontinuities that become sharper as the temperature is lowered. The discontinuities are the result of an elementary catastrophe that occurs as the phase space available for the decay varies with frequency. They should be observable, for instance, as dramatic changes in the out-of-plane spin-wave linewidth in CsNi${\mathrm{F}}_{3}$ as a function of temperature and wave vector.
Comparative Surgical Outcomes for Endometrial Cancer Patients 65 Years Old or Older Staged With Robotics or Laparotomy

This study aimed to assess the safety of robotic surgery for older women undergoing surgery for endometrial cancer. A retrospective chart review of women undergoing surgery for endometrial cancer between October 2010 and December 2012 was conducted at the authors’ institution. This cohort was divided by age (≥65 vs <65 years) and surgical approach (laparotomy vs robotic surgery). Postoperative morbidity and mortality were compared using standard statistical analysis. Of 228 patients identified, 73 (32 %) were 65 years old or older, and 98 (43 %) had undergone robotic surgery. Among the robotic surgery patients, women 65 years old or older had a higher Charlson comorbidity score (7.6 vs 4.9; p < 0.01) and were more likely to undergo pelvic lymphadenectomy (73 vs 39 %; p < 0.01). The complication rates did not differ between the groups except for increased urinary retention in the older group (15 % vs 3 %; p = 0.04). Older patients had a longer hospital stay (2.2 vs 1.3 days; p < 0.01) and a similar rate of discharge home (100 vs 96 %; p = 0.09). For the patients 65 years old or older, robotic surgery was associated with less blood loss (131 vs 235 ml; p = 0.03), a lower rate of ileus (0 vs 15 %; p = 0.04), a lower perioperative surgical complication rate (4 vs 30 %; p = 0.01), a shorter hospital stay (2.2 vs 4.4 days; p < 0.01), and a similar rate of discharge home (96 vs 91 %; p = 0.45) compared with laparotomy. Robotic surgery appears to be associated with less postoperative morbidity than laparotomy for endometrial cancer staging in women 65 years old or older. The complication rates after robotic surgery were similar between the two age groups.
Crystal structure of macrophage migration inhibitory factor complexed with (E)-2-fluoro-p-hydroxycinnamate at 1.8 A resolution: implications for enzymatic catalysis and inhibition.

Macrophage migration inhibitory factor (MIF) exhibits dual activities. It acts as an immunoregulatory protein as well as a phenylpyruvate tautomerase. To understand better the relationship between these two activities and to elucidate the structural basis for the enzymatic activity, a crystal structure of a complex between murine MIF and (E)-2-fluoro-p-hydroxycinnamate, a competitive inhibitor of the tautomerase activity, has been determined to 1.8 A resolution. The structure is nearly superimposable on that of the free protein indicating that the presence of the inhibitor does not result in any major structural changes. The inhibitor also confirms the location of the active site in a hydrophobic cavity containing the amino-terminal proline. Within this cavity, the inhibitor interacts with residues from adjacent subunits. At the back of the cavity, the side-chain carbonyl oxygen of Asn-97‘ interacts with the phenolic hydroxyl group of the inhibitor while at the mouth of the cavity the ammonium group of Ly...
Development of a Networked Blood Pressure Monitoring System

Healthcare costs are expected to increase at double-digit rates in the coming years. Cardiovascular disease is the primary cause of death of males in the U.S. and consumes a large share of these healthcare dollars. If untreated, hypertension can lead to heart attack or even death. If detected early, hypertension can often be reversed through diet, exercise, and pharmaceuticals, thus reducing the likelihood of catastrophic disease, hospitalization, and death. The objective of this project was to develop and implement a work-based network environment at Southwest Research Institutereg (SwRIreg) to monitor the arterial health of SwRI employees. The goal of this implementation was to establish a network of existing medical devices and to investigate improving employee health through use of the developed network. Existing blood pressure monitors were modified and connected to the SwRI network. A Web-based system was developed using open source software components and LabVIEWtrade to collect data measured by the blood pressure equipment and to present the collected data to the users. A total of 109 SwRI employees were enrolled in the program. Over a 7(1/2) month period during which blood pressure stations were installed, 1705 blood pressure measurements were obtained. The average systolic and diastolic measurements were 124 and 74, respectively, and 85% of the measurements were either normal or prehypertensive. Overall, 63.3% of the participants utilized a single blood pressure station to obtain measurements, usually the one closest to where they worked
Fragility of an Isochorically Confined Polymer Glass

We report the effect of isochoric confinement on the dynamic fragility of a polymeric glass-former, that is, polystyrene (PS). Utilizing silica-capped PS nanospheres as a model system, the fictive temperature (Tf) and the isochoric heat capacity (Cv) are measured as a function of diameter via differential scanning calorimetry. By examining Tf as a function of cooling rate for each sample, the isochoric fragility (mv) is obtained, which decreases significantly as the diameter of the nanospheres is reduced from 260 to 129 nm. Hence, the temperature dependence of structural relaxation near the glass transition is weakened with isochoric confinement.
The Development of a Suspension-Type Insulator

Increasing voltages employed in transmitting large amounts of power over long distances emphasize the need of a better line insulator for this purpose. This paper outlines the conditions under which a suspension-type insulator has been experimentally developed for such use. In the form described, it consists of metallic terminal members to suitably distribute the electric flux and an insulating, impregnated wood (or other material) mechanical strain member, concentric with the hollow electric field produced between the metallic terminal members. The unit described is designed for use on 110,000-volt power lines, two similar units in series for 220,000-volt lines and, when necessary, three units in series on 330,000-volt lines. The fundamental principles of the insulator are established and later continued experience in service may or may not modify detail.
The bounded quartic oscillator

Abstract The eigenvalues of the pure quartic oscillator bounded by infinitely high potentials are studied. Compact recursion relations for the power series coefficients of the odd and the even wave functions are obtained which allow numerical values of the eigenvalues to be computed via an iteration scheme.
A model for coupled sulfate reduction and methane oxidation in the sediments of Saanich Inlet

Abstract A methane-sulfate coupled reaction diffusion model has been developed to describe the inverse relationship commonly observed between methane and sulfate concentrations in the pore waters of anoxic marine sediments. The sediment column was divided into two zones; an upper zone where diagenetic reaction rates are limited by the concentration of oxidizable organic matter and a lower zone in which reaction rates are limited by the concentration of oxidizing agent—sulfate. For each zone differential equations describing the distribution of methane and sulfate were derived. The boundary conditions used to solve these equations resulted in a set of four coupled equations. When fit to data from Saanich Inlet (B.C., Canada) and Skan Bay (Alaska) the model not only reproduces the observed methane and sulfate pore water concentration profiles but also accurately predicts the methane oxidation and sulfate reduction rates. Maximum methane oxidation rates occur at the transition boundary from the upper to the lower layer. In Saanich Inlet sediments from 23 to 40% of the downward sulfate flux is consumed in methane oxidation while in Skan Bay this value is only about 12%.
Modeling Orientation-Constrained Reactions: A Study Of Crowding Effects With Brownian Dynamics Simulation

Specific protein-binding is essential for biochemical reactions in cell signaling. To understand the effects of the intracellular crowding environment on the kinetics of such specific binding, we studied anisotropic interactions in a simple crowded model system composed of hard spheres with effective charges interacting through a Yukawa-type potential, to model the orientation-constrained specific protein binding process. Utilizing Brownian dynamics simulations, our studies on a monodisperse system indicate that although the diffusion of each molecule is slowed down in the crowded environment, the rate constant for the diffusion-limited orientation-constrained reaction is increased. For a charged-molecule system this speed-up could reach up to 4-fold at about 38% solute volume fraction, compared to the same reaction in the dilute solution. Crowding not only reduces the time to the “first binding” event, but also greatly reduces the average re-binding time, thus increasing the chemistry-limited reaction rate. For the same charged-molecule system, the re-binding time is also reduced significantly, up to 100-fold. Assuming 0.001 ∼ 0.01 reaction probability for each specific binding, these simulation results imply a full order of magnitude enhancement for the rate constant of the chemistry-limited reactions. These significant effects of the crowding environment on the reaction rate depend both on the direct interactions between the tracer molecule and the crowding molecules, and on the interactions among the crowding molecules. In general, we find that the repulsive interaction between the tracer and crowding molecules has stronger “caging” effects on the acceleration of the reaction. The quantitative information obtained even from such a simple set of model systems indicates the directions and expected range of changes in the magnitude of important parameters used in the quantitative study of corresponding processes involving complex proteins, and advances the realistic modeling of cellular processes.
Cholesterol biosynthesis in rabbit blood and bone marrow: Effect of hematopoietic stimulation and dietary cholesterol

Abstract The incorporation of significant amounts of [1-14C]acetate into cholesterol occurred in normal rabbit bone marrow, leucocytes, reticulocytes and platelets, in vivo and in vitro. Erythropoietic stimulation from phenylhydrazine injection and phlebotomy was associated with hyperlipemia and hypercholesterolemia. Increased hepatic cholesterol incorporation of 14C from [1-14C]acetate was observed in phlebotomized rabbits, but not in those injected with phenylhydrazine. Under stimulation mixed marrow cells incorporated 2–3 times more [1-14C]acetate into cholesterol, in vivo, than those of control rabbits. Blood and bone marrow from rabbits previously stimulated hematopoietically were capable of incorporating, in vitro, significantly more [1-14C]-acetate into cholesterol than controls. From in vitro experiments, leucocytes, reticulocytes and platelets were estimated to account for 65.7%, 26.9% and 7.4% of the cholesterol synthetic activity of normal rabbit blood. Male rabbits were fed a 0.35% cholesterol-containing diet for periods up to 98 days. The rate of cholesterol synthesis from [1-14C]acetate by bone marrow cells, in vitro, was found to be significantly depressed after 14 days of feeding. The cholesterol content of bone marrow cells increased in proportion to the rise in plasma cholesterol concentration. Early in the feeding period (0–14 days) an inverse linear relationship between the logarithm of the rate of cholesterogenesis and cholesterol content of the bone marrow cells was observed. An increase of 0.4 mg/ml of packed cells resulted in a 50% decrease in the rate of incorporation of [1-14C]acetate into cholesterol. Bone marrow cells, pre-incubated in hyperlipemic plasma for 3 h, incorporated nearly 50% less [1-14C]acetate into cholesterol than those pre-incubated in normal plasma, whereas non-cholesterol lipid incorporation was not depressed.
United States statistics on exports and imports

Collection and reporting of U.S. import and export data have been continuously refined to better serve the publishing industry and to be compatible with the efforts of other nations. Despite these efforts, limitations remain on the ways in which international statistics can be used. These limitations arise from problems of categorization, exemption of low-valued shipments from reporting requirements, the difficulties of dealing with transshipments, and the inadequacy of reporting on translations and sales of foreign rights. *** DIRECT SUPPORT *** A05BB007 00002
Juvenile Hormone Diol Kinase I. PURIFICATION, CHARACTERIZATION, AND SUBSTRATE SPECIFICITY OF JUVENILE HORMONE-SELECTIVE DIOL KINASE FROM MANDUCA SEXTA

Manduca sexta juvenile hormone diol kinase (JHDK) catalyzes the conversion of juvenile hormone (JH) diol to JH diol phosphate. JHDK may be the first example of a phosphotransferase directly involved in the catabolism and inactivation of a lipid-soluble hormone. JHDK is an enzyme crucial for secondary metabolism of JH and possesses high specificity and catalytic efficiency for JH diol. In this study, the purification and characterization of native JHDK are described; its enzymatic properties are examined; and its role in cellular JH metabolism is explored. Using a variety of potential substrates, we show that JHDK has a preference for ATP, but will catalyze the formation of JH diol phosphate with GTP as the phosphate donor. JHDK has a nanomolar Km for JH I diol and a low micromolar value for MgATP. JH II and III diols also serve as phosphate acceptors with low micromolarKm, whereas other diol derivatives of terpenoid esters structurally similar to JH metabolites are not phosphorylated. The reaction proceeds via a sequential Bi Bi mechanism. JHDK is active as a homodimer with a subunit molecular mass of 20 kDa. JHDK binds 5′-p-fluorosulfonylbenzoyladenosine and is inhibited by micromolar levels of Ca2+.
The heparin-binding exosite of factor IXa is a critical regulator of plasma thrombin generation and venous thrombosis

The role of the factor IXa heparin-binding exosite in coagulation was assessed with mutations that enhance (R170A) or reduce (R233A) stability of the protease-factor VIIIa A2 domain interaction. After tissue factor (TF) addition to reconstituted factor IX-deficient plasma, factor IX R170A supported a 2-fold increase in velocity index (slope) and peak thrombin concentration, whereas factor IX R233A had a 4- to 10-fold reduction relative to factor IX wild-type. In the absence of TF, 5 to 100 pM of factor IXa increased thrombin generation to approach TF-stimulated thrombin generation at 100% factor IX. Factor IXa R170A demonstrated a 2- to 3-fold increase in peak thrombin concentration and 5-fold increase in velocity index, whereas the response for factor IXa R233A was blunted and delayed relative to wild-type protease. In hemophilia B mice, factor IX replacement reduced the average time to hemostasis after saphenous vein incision, and the time to occlusion after FeCl3-induced saphenous vein injury. At 5% factor IX, the times to occlusion for factor IX wild-type, R170A, and R233A were 15.7 minutes, 9.1 minutes (P ≤ .003), and more than 45 minutes. These data support the role of the factor IXa heparin-binding exosite as a critical regulator of coagulation and novel antithrombotic target.
Agency and Institutions: The Enabling Role of Individuals’ Social Position:

Although early neo-institutional studies did not explicitly tackle the issue of agency, more recent studies about institutional entrepreneurship have brought it to the forefront. Institutional entrepreneur-ship has been presented as a promising way to account for institutional change endogenously. However, this notion faces the paradox of embedded agency. To overcome this paradox, it is necessary to explain under what conditions actors are enabled to act as institutional entrepreneurs. Some neo-institutional theorists have already addressed this issue. Their studies focus mainly on the organizational and organizational field levels of analysis. In this paper, I aim to complement their work by examining under what conditions individuals are more likely to engage in institutional entrepreneurship. By doing so, I take into account the individual level of analysis that neo-institutional theorists often tend to neglect. Relying on Bourdieu’s conceptualization of fields, I propose that individuals’ social posit...
A 1-kb Bacteriophage Lambda Fragment Functions as an Insulator to Effectively Block Enhancer–Promoter Interactions in Arabidopsis thaliana

Enhancers are known to be capable of overriding the specificity of nearby promoters in a distance-dependent manner, which is problematic when multiple promoters coexist in a single transgene unit. In an attempt to determine whether enhancer activation function is inversely related to its distance from the target promoter, we inserted 1-, 2-, and 4-kb bacteriophage λ fragments, respectively, between the cauliflower mosaic virus 35S enhancer and a flower-specific AGAMOUS second intron-derived promoter (AGIP) fused to the β-glucuronidase (GUS) coding region. In the absence of an insert sequence, the 35S enhancer activates AGIP-driven GUS expression in vegetative tissues of transgenic Arabidopsis thaliana lines. Moreover, neither the 2-kb nor the 4-kb λ fragment was able to block GUS expression in transgenic leaves, implying that the 35S enhancer can override a distance barrier of at least 4 kb in our system. Unexpectedly, insertion of the 1-kb λ insert into the same site resulted in diminished GUS expression in transgenic leaves. Our data indicate that this fragment functions as a true enhancer-blocking insulator that could potentially be utilized to minimize enhancer-promoter interference between multiple transcriptional units within a plasmid vector during plant transformation experiments.
Weak-interaction effects in heavy atomic systems. II.

Evaluations of parity-violating and charge-parity--violating effects in heavy one-valence-electron atoms, employing the Hartree-Fock potential and several model potentials, are extended to include first-order electron-electron Coulomb corrections using many-body perturbation theory. Parity-conserving quantities, including valence energies, hyperfine splittings, and oscillator strengths, are also calculated and compared with experiment to determine the reliability of the weak-interaction calculations. It is found that the spread between calculations carried out in first-order perturbation theory starting from different potentials is of the same order of magnitude as the spread between the corresponding lowest-order evaluations. It is concluded that second-order many-body perturbation theory must give significant contributions. Some technical problems associated with going to second order are discussed.
Evaluation of acupuncture in the treatment of Parkinson's disease: A double‐blind pilot study

As many as 40% of patients with Parkinson's disease (PD) use some form of complementary medicine during the course of their illness, and many try acupuncture. One nonblinded study of the effects of acupuncture in PD suggested that it might be helpful for some aspects of PD. We performed a double-blind, randomized, pilot study comparing acupuncture to a control nonacupuncture procedure to determine the effects of acupuncture upon a variety of PD-associated symptoms. Fourteen patients with Stage II or III PD received acupuncture or a control nonacupuncture protocol. Before and after treatment, patients were evaluated using the Motor subscale of the Unified Parkinson's Disease Rating Scale (UPDRS), the Parkinson's Disease Questionnaire (PDQ-39), and the Geriatric Depression Scale. There were no statistically significant changes for the outcomes measured. In the patients who received acupuncture, nonsignificant trends toward improvement were noted in the Activities of Daily Living score of the PDQ-39, the PDQ-39 Summary Index(c) 2005 Movement Disorder Society.
Paramedic Training for Proficient Prehospital Endotracheal Intubation

AbstractBackground. Emergency airway management is an important component of resuscitation of critically ill patients. Multiple studies demonstrate variable endotracheal intubation (ETI) success by prehospital providers. Data describing how many ETI training experiences are required to achieve high success rates are sparse. Objectives. To describe the relationship between the number of prehospital ETI experiences and the likelihood of success on subsequent ETI and to specifically look at uncomplicated first-pass ETI in a university-based training program with substantial resources. Methods. We conducted a secondary analysis of a prospectively collected cohort of paramedic student prehospital intubation attempts. Data collected on prehospital ETIs included indication, induction agents, number of direct laryngoscopy attempts, and advanced airway procedures performed. We used multivariable generalized estimating equations (GEE) analysis to determine the effect of cumulative ETI experience on first-pass and o...
Diet and Cancer Prevention Studies in p53-Deficient Mice

Progress in mechanism-based cancer prevention research may be facilitated by the use of animal models displaying specific genetic susceptibilities for cancer such as mice deficient in the p53 tumor suppressor gene, the most frequently altered gene in human cancer. We observed in p53-knockout (p53-/-) mice that calorie restriction (CR; 60% of the control group's intake of carbohydrate energy) increased the latency of spontaneous tumor development (mostly lymphomas) ∼75%, decreased serum insulin-like growth factor (IGF)-1 and leptin levels, significantly slowed thymocyte cell cycle traverse and induced apoptosis in immature thymocytes. In heterozygous p53-deficient (p53+/-) mice, CR and 1 d/wk of food deprivation each significantly delayed spontaneous tumor development (a mix of lymphomas, sarcomas and epithelial tumors) and decreased serum IGF-1 and leptin levels even when begun late in life. We have also developed a rapid and relevant p53+/- mouse mammary tumor model by crossing p53-deficient mice with MMTV-Wnt-1 transgenic mice, and found that CR and 1 d/wk food deprivation significantly increased mammary tumor latency (greater than twofold) and reduced the mean serum IGF-1 and leptin levels to <50% of that of control mice (P < 0.0001). In addition, fluasterone, fenretinide and soy each delayed tumor development but had little effect on IGF-1 or leptin levels. We have capitalized on the susceptibility of p53+/- mice to chronic, low dose, aromatic amine-induced bladder carcinogenesis to develop a useful model for evaluating bladder cancer prevention approaches such as cyclooxygenase-2 inhibition. As demonstrated by these examples, mice with specific (and human-like) genetic susceptibilities for cancer provide powerful new tools for testing and characterizing interventions that may inhibit the process of carcinogenesis in humans.
Thrombin formation in vitro in response to shear-induced activation of platelets.

Abstract Introduction Thromboembolic events caused by implanted vascular devices present serious medical challenges. In particular bileaflet mechanical heart valves (MHVs) are prone to thrombus formation in the hinge region due to a combination of high shear stress and stagnation regions. Most studies of shear-induced platelet activation and aggregation have been performed using viscometers, parallel plate flow, and other non-physiologic in vitro configurations. The present study investigated these events in a physiogically relevant environment in which thrombin formation in response to shear stress activation of platelets plays a more predominant role. Materials and methods Anticoagulated (citrated) human blood was placed in a steady flow loop containing a 400 μm round orifice or various MHVs in the leakage position. Simultaneous blood recalcification enhanced the thrombus forming potential of the blood. Aggrastat and AN51 were used to block binding to the platelet GPIIb/IIIa and GPIb receptors, respectively, and aspirin was used to block thromboxane production. Thrombin generation was measured indirectly by the thrombin-antithrombin III assay. Results and conclusions Aggrastat, AN51, and aspirin all suppressed thrombin formation. Furthermore, histological results suggested important roles for vWF and fibrinogen in a two-step model of thrombus formation. Thus, thrombin is reproducibly formed in this in vitro system, a process that can be suppressed by blocking platelet activation. This system has the potential to investigate mechanisms and interventions for medical devices that contact with blood under varying shear stress conditions.