cssi/SciSciGPT-SciSciNet huggingface dataset:
Some reactions of an o-quinone monoimide with derivatives of furan and styrene†

Diels-Alder-type cycloaddition reactions occur across the heterodiene system of the o-quinone monoimide 1 when 1 is treated with the furans visnagin and 8-methoxypsoralen. Derivatives of a new heterocyclic system are formed. Similar cycloadditions take place between the heterodiene moiety of 1 and the olefinic linkages present in 7-methoxy-2,4-dimethyl-3-chromene (precocene I) and indene. In the former case another ring system previously uncharacterized was produced. Precocene I also reacted with o-chloranil and an o-quinone diimide to yield a benzopyrano[3,4-b] [1,4]benzodioxin and a benzopyrano[3,4-b]quinoxaline respectively.
Polymer-Based Catch-Bonds

Catch-bonds refer to the counterintuitive notion that the average lifetime of a bond has a maximum at a nonzero applied force. They have been found in several ligand-receptor pairs and their origin is still a topic of debate. Here, we use coarse-grained simulations and kinetic theory to demonstrate that a multimeric protein, with self-interacting domain pairs, can display catch-bond behavior. Our model is motivated by one of the largest proteins in the human body, the von Willebrand Factor, which has been found to display this behavior. In particular, our model polymer consists of a series of repeating units that self-interact with their nearest neighbors along the chain. Each of the units mimics a domain of the protein. Apart from the short-range specific interaction, we also include a linker chain that will hold the domains together if unbinding occurs. This linker molecule represents the sequence of unfolded amino acids that connect contiguous domains, as is typically found in multidomain proteins. The units also interact with an immobilized ligand, but the interaction is masked by the presence of the self-interacting neighbor along the chain. Our results show that this model displays all the features of catch-bonds because the average lifetime of a binding event between the polymer and the immobilized receptor has a maximum at a nonzero pulling force of the polymer. The effects of the energy barriers for detaching the masking domain and the ligand from the binding domain, as well as the effects of the properties of the polypeptide chain connecting the contiguous domains, are also studied. Our study suggests that multimeric proteins can engage in catch-bonds if their self-interactions are carefully tuned, and this mechanism presumably plays a major role in the mechanics of extracellular proteins that share a multidomain character. Furthermore, our biomimetic design clearly shows how one could build and tune macromolecules that exhibit catch-bond characteristics.
Group 2 element β-diketonate complexes: synthetic and structural investigations

Abstract An overview of the Group 2 element β-diketonates is presented, including their synthesis, structural characteristics, physical properties, and some potential applications.
The flexible magnetic field thruster

The flexible magnetic field thruster is a unique research tool for studying the behavior of direct current electron-bombardment ion thrusters. It utilizes a long wire anode shielded by a circumferential magnetic field. The magnetic field around the anode, which is produced by passing a direct current of up to 150 A through the wire, restricts primary electron flow from the discharge plasma to the anode. Different magnetic field configurations (divergent, cusped, multipole, etc.) can be created by routing the anode wire in various ways through the discharge chamber. The thruster is also designed so ion currents to various internal surfaces can be measured directly. This allows the determination of the distribution of ion currents within the discharge chamber. Experiments indicate that the distribution of ion currents is strongly dependent on the shape and strength of the magnetic field but independent of the discharge current, discharge voltage, and neutral flow rate. Measurements of the energy cost per plasma ion indicate that this cost decreases with increasing magnetic field strength due to increased anode shielding from the primary electrons. Energy costs per argon plasma ion as low as 50 eV were measured. The energy cost per beam ion was found to be a function of the energy cost per plasma ion, extracted ion fraction, and discharge voltage. Part of the energy cost per beam ion goes into creating many ions in the plasma and then extracting only a fraction of them into the beam. The rest of the energy goes into accelerating the remaining plasma ions into the walls of the discharge chamber. Measurement of ion fluxes across a virtual anode surface appears to indicate that ions cross this surface with velocities approaching their random thermal velocity rather than the Bohm velocity.
Ranges of Atmospheric Mass and Composition of Super-Earth Exoplanets

Terrestrial-likeexoplanets may obtainatmospheres from three primary sources:capture of nebulargases,degassing during accretion, and degassing from subsequent tectonic activity. Here we model degassing during accretion to estimate the range of atmospheric mass and composition on exoplanets ranging from 1 to 30 Earth masses. We use bulk compositions drawn from primitive and differentiated meteorite compositions. Degassing alone can create a widerangeof massesof planetaryatmospheres,rangingfromlessthan1%of theplanet’stotalmassupto � 6percent bymass (mass%) of hydrogen, � 20 mass% of water, and/or � 5mass% of carbon compounds. Hydrogen-rich atmospheres can be outgassed as a result of oxidizing metallic iron with water, and excess water and carbon can produce atmospheres through simple degassing. As a byproduct of our atmospheric outgassing models we find that modest initial water contents (10 mass% of the planet and above) create planets with deep surface liquid water oceans soon after accretion is complete. Subject headingg accretion, accretion disks — planets and satellites: formation — solar system: formation Online material: color figures
Effects of friction and heat conduction on sound propagation in ducts

The theory of sound propagation is examined in a viscous, heat-conducting fluid, initially at rest and in a uniform state, and contained in a rigid, impermeable duct with isothermal walls. Topics covered include: (1) theoretical formulation of the small amplitude fluctuating motions of a viscous, heat-conducting and compressible fluid; (2) sound propagation in a two dimensional duct; and (3) perturbation study of the inplane modes.
Cones, Pringles, and Grain Boundary Landscapes in Graphene Topology

A polycrystalline graphene consists of perfect domains tilted at angle α to each other and separated by the grain boundaries (GB). These nearly one-dimensional regions consist in turn of elementary topological defects, 5-pentagons and 7-heptagons, often paired up into 5−7 dislocations. Energy G(α) of GB computed for all range 0 ≤ α ≤ π/3, shows a slightly asymmetric behavior, reaching ∼5 eV/nm in the middle, where the 5′s and 7′s qualitatively reorganize in transition from nearly armchair to zigzag interfaces. Analysis shows that two-dimensional (2D) nature permits the off-plane relaxation, unavailable in three-dimensional (3D) materials, qualitatively reducing the energy of defects on one hand while forming stable 3D landscapes on the other. Interestingly, while the GB display small off-plane elevation, the random distributions of 5′s and 7′s create roughness that scales inversely with defect concentration, h ∼ n−1/2.
Spatiotemporal Shaping of Terahertz Pulses

We report temporal shaping of few-cycle terahertz pulses, using a slit in a conductive screen as a high-pass filter. The filter’s cutoff frequency was tuned by changing the width of the slit; the slope of the cutoff transition was altered by changing the thickness of the screen. We measured the transmission function of the filters, using large-aperture photoconducting antennas to create and detect the incident and transmitted electric field. Our experimental results were in excellent agreement with the performed finite-difference time-domain simulations of the propagation of the pulse through the slit. When the screen thickness was greater than the slit width, the filter was well modeled by a short, planar waveguide. Using a simple transfer function, we accurately describe the sharp cutoff and dispersion of such a filter. © 1997 Optical Society of America Recently terahertz (THz) pulses have proved useful for a wide variety of applications, including far-infrared 1 / time-domain spectroscopy, 2 study and control of Rydberg atoms, 3 T-ray imaging of optically opaque materials, 4 and impulse-ranging studies. 5 Applications exploit the features of THz pulses that distinguish them from optical pulses, namely their broad bandwidth and long center wavelength. The broad bandwidth allows for the exciting possibility for sculpting the pulses to meet a desired goal by modifying their spectra. Although shaped THz pulses have been made by modifying the optical pump intensity profile 6 or by manufacturing more complex emitters, 7 there are
Magnetism of doped CuGeO3

Abstract A review of the recent neutron scattering experiments on doped Cu(Zn,Mg)Ge(Si)O 3 is presented. A unique antiferromagnetic (AF) ordering co-exists with the spin-Peierls ordering (SP) and their spin wave profiles were characterized by inelastic neutron scattering. Very recently a novel phase diagram was proposed by Masuda et al. for Cu 1− x Mg x GeO 3 . At the critical concentration of 2.3% Mg, the SP phase suddenly disappears and only the AF phase remains at a higher x . The neutron scattering work by Nakao et al. further characterizes this interesting phase diagram.
A parallel programming environment supporting multiple data-parallel modules

We describe a system that allows programmers to take advantage of both control and data parallelism through multiple data-parallel modules. This system extends C-type stream I/O to include inter-module communication channels. The programmer writes each module separately, then develops a specification that instructs the system how to connect the modules together. Our current system extends the Dataparallel C language and runs on the Intel iWarp computing system.
Generalized formulation for performance degradations due to bending and edge scattering loss in microdisk resonators

We present a generalized formulation for the treatment of both bending (whispering gallery) loss and scattering loss due to edge roughness in microdisk resonators. The results are applicable to microrings and related geometries. For thin disks with radii greater than the bend-loss limit, we find that the finesse limited by the scattering losses induced by edge roughness is independent of radii. While a strong lateral refractive index contrast is necessary to prevent bending losses, unless the radii are of the order of a few microns, lateral air-cladding is detrimental and only enhances scattering losses. The generalized formulation provides a framework for selecting the refractive index contrast that optimizes the finesse at a given radius.
Mixed H2/H-infinity optimal control for an elastic aircraft

A mixed //2/floo optimal control design and its application to a flight control problem of B-l aircraft is studied. The mixed #2/ 00 optimal control design is one of finding an internally stabilizing controller that minimizes the //2/#oo performance index subject to an inequality constraint on H^ norm. The application is a linear model of longitudinal motion of B-l aircraft. A standard eigenvalue problem that involves linear matrix inequalities is formulated, and efficient interior point algorithms are used to solve this problem numerically. Results show that this mixed //2/#oo optimal design leads the designer into a tradeoff between HI and HQQ objectives. Through this method, a designer can determine the controllers that result in the desired closed-loop noise rejection properties and stability robustness.
Improving detection of violence among pregnant adolescents

Purpose: The purpose of this study was to determine whether a systematic assessment protocol could increase reporting of violence among pregnant adolescents compared with a routine prenatal assessment. This study also sought to examine issues related to violence assessment among maternity care coordinators. Methods: The Maternity Care Coordination (MCC) program in a health department prenatal clinic in North Carolina routinely screened all clients for violence at their first visit. This assessment was not standardized. In 1994, the MCC program implemented a systematic violence assessment protocol for all adolescents ( n = 117). The protocol assessed violence at three points during pregnancy by asking one direct question: "Have you been hit, slapped, kicked, or hurt during this pregnancy?" To examine the effectiveness of the system, we retrospectively reviewed the 1993 MCC records in which the coordinators routinely screened clients for violence ( n = 129). To examine issues related to screening, we conducted in-depth interviews with the maternity care coordinators. Results: The routine pre-intervention assessment indicated that 5.4% of adolescents 12–19 years of age reported prenatal violence. The systematic assessment protocol resulted in a significant increase in reported violence from 5.4% to 16.2% (odds ratio=2.9, 95% confidence interval=1.6, 5.6, adjusted for race). Maternity care coordinators identified five factors related to increased reporting using the standardized protocol: (a) written protocol and data collection form; (b) asking direct, specific questions; (c) not labeling the victim; (d) not naming the perpetrator; and (e) conducting multiple assessments. Conclusions: Multiple, direct, systematic assessments throughout prenatal care resulted in increased reporting of prenatal violence among adolescents compared to single, routine, nonstructured assessments.
Analysis of Turbulent Boundary Layer on Cascade and Rotor Blades of Turbomachinery

The momentum integral technique for predicting the boundary-layer growth in three-dimensi onal flow has been extended to include the entrainment equation as the closure model. The numerical solution is compared with the cascade, inducer, compressor, and fan rotor blade data from various sources. The agreement is found to be excellent in all cases, with the exception of the separated flow. Both the momentum thickness and the limiting streamline angle predicted from this analysis compare well with the measured data for a rotor blade. The technique is extremely useful in engineering design, analysis, and performance prediction.
Oriented Quantum Algebras and Invariants of Knots and Links

Abstract In our previous work oriented quantum algebras were motivated and introduced in a very natural categorical setting within the context of knots and links, some examples were discussed, and a rudimentary theory of oriented quantum algebras was sketched. Invariants of knots and links can be computed from oriented quantum algebras. Here we continue the study of oriented quantum algebras. We view them from a more algebraic perspective and develop a more detailed theory for them and their associated invariants. We study a class of examples associated with the HOMFLY polynomial in depth.
Submersible pumping--long beach unit of east wilmington field: A 17-year review

The electric submersible pump (ESP) was selected as the primary form of lift when Thums Long Beach Co. initiated production operations in Aug. 1965. Deviated wells with ever increasing volumes resulting from waterflooding required the flexibility offered by this lift method. Many problems have been solved in the 17 years of these operations to provide a respectable run life and a sound economic operational basis.
Classical/Neural Synthesis of Nonlinear Control Systems

Classical/neural synthesis of control systems combines the most effective elements of old and new design concepts with the promise of producing better control systems. There is considerable precedent for applying gain-scheduled linear controllers to nonlinear systems, especially those that can be locally approximated as linear-parameter-varying systems; however, a means for transferring the insights gained from these linear controllers to nonlinear controllers remains to be identified. The approach taken here is to design nonlinear control systems that take advantage of prior knowledge and experience gained from linear controllers, while capitalizing on the broader capabilities of adaptive, nonlinear control theory and computational neural networks. Central to this novel approach is the recognition that the gradients of a nonlinear control law must represent the gain matrices of an equivalent, locally linearized controller. In this paper we focus on the initial specification for the control law, which consists of a set of hypersurfaces expressed as neural networks that represent satisfactory linear controllers designed over the plant's operating range. Along the way, a new neural network training method consisting solely of solving algebraic linear systems of equations is developed, and its effectiveness is demonstrated on a case study.
Development of an Integrated BEM for Hot Fluid-Structure Interaction

A boundary element approach is developed for problems of hot fluid-structure interaction. The structure is idealized as a thermoelastic solid, and a time-domain, boundary-only integral formulation is described. Meanwhile, several approaches are discussed for the hot fluid. Integrals equations are developed for both compressible and incompressible thermoviscous flow. Due to the presence of nonlinear convective terms in the governing differential equations, domain discretization is generally required. However, with the introduction of reference velocities, volume modeling often can be confined to regions near obstacles and walls. All formulations are implemented for two-dimensional problems in GPO-BEST, a general purpose boundary element computer program. An overview of this numerical implementation is provided, along with several illustrative examples. The present fluid formulations are appropriate in the low to medium Reynolds number ranges; however, some enhancements required for higher speed simulations are noted.
Dynamic multivalent lactosides displayed on cyclodextrin beads dangling from polymer strings.

Lactose-appended cyclodextrin derivatives have been synthesized and threaded onto hydrophobic polymers in aqueous solution to form dynamic multivalent lactosides for binding to lectins. The threading process, which proceeds quickly, can be observed by one- and two-dimensional NMR spectroscopies.
Corrosion of mild steel subjected to alternating voltages in seawater

Abstract Relatively little information is available on corrosion of materials in marine environment under the influence of AC fields. In this study, corrosion caused by sinusoidal alternating voltage (AV) fields in 1018 carbon steel is investigated by: (i) immersion tests and (ii) characterization of corrosion products. The experimental data show that under the influence of alternating voltage (60 Hz) applied between carbon steel and a platinum mesh counter electrode, the corrosion rate of the carbon steel increases with the applied voltage then decreases as the peak voltage amplitude is increased in the range 100–600 mV. With a further increase in the voltage amplitude beyond 600 mV, the corrosion rate is observed to increase exponentially. It is speculated that the decrease in the corrosion rate is related to a passivation phenomena brought about by an increase in the pH of the diffusion layer. The influence of the pH on the carbon steel corrosion properties is also investigated. The effect of frequency of AV signal on corrosion rate is also determined and discussed.
GEOMETRY OF THE COMPLEX OF CURVES II: HIERARCHICAL STRUCTURE

This paper continues a geometric study of Harvey's Complex of Curves, whose ultimate goal is to apply the theory of hyperbolic spaces and groups to algorithmic questions for the Mapping Class Group and geometric properties of Kleinian representations. The authors' previous result that the complex is delta-hyperbolic was hard to apply because the complex is not locally finite; in this paper some tools are developed for overcoming this problem, and a combinatorial mechanism introduced which describes sequences of elementary moves in the graph of markings on a surface. These tools are applied to give a family of quasi-geodesic words in the Mapping Class Group, and a linear bound on the shortest word conjugating two conjugate pseudo-Anosov elements. A basic tool in the analysis is a family of subsurface projections, which are roughly analogous to closest-point projections to horoballs in classical hyperbolic space. These projections have a strong contraction property which makes it possible to tie together the geometry of the complex and that of the (infinite) subcomplexes that arise as links of vertices. The resulting layered structure of the complex is controlled by means of a combinatorial device called a hierarchy of geodesics, which is the central construction of the paper.
A decision model for the estate management problem

Estate management planning requires the development of a comprehensive plan (a) to insure successful economic management of the estate property during and after the lifetime of the owner, and (b) to produce the desired legal consequences in the disposition of the property after death. For adequate analysis, both changes in the ownership and in the size of the estate over time and the uncertainty of the death of the testators must be considered. This paper develops a dynamic decision model that can be used to evaluate how well alternative legal and financial tools satis fy specified estate-management goals. The conceptual model is stated in mathematical form and is trans formed into a stochastic, multistage computer simula tion model. The paper includes an example illustra ting the use of simulation in a practical case.
Chemical dosimetry in the near-zone of brachytherapy sources

The treatment of neointimal-hyperplasia, prostate cancer with 125 I seed implants, and transition zone effects in three-dimensional conformal therapy has spurred the development of new dosimeters for evaluating steep dose-gradient regions. This thesis describes two dosimetry systems to accurately measure the radial dose in the near-zone ( 137 Cs and 192 Ir sources. A custom-made polymergeldosimeter was designed and implemented for this project. This dosimeter evaluated with a high field strength small-bore MR(Magnetic Resonance)scanner provided precise measurement of the dose in the near-zone. A second system consisted of gaf-chromic film and a custom-built precision scanner. The scanner, using a 670 nm diode laser and precision built micrometers, provided precise scanning of the gaf-chromic film. The gaf-chromic filmdosimetry system gave results that were in good agreement (2%) with the polymergeldosimeter for the radial dose in the near-zone of clinically used 137 Cs and 192 Ir sources. The radial dose data from both dosimetry systems agreed to within 3% with Monte Carlo data at radial distances of less than 5 mm from the center of single 137 Cs and 192 Ir sources. This project has extended the reliable data in the near-zone to 1 mm for 192 Ir . Both dosimeters were shown to be satisfactory for near-zone dosimetry, and provide an empirical benchmark for the Monte Carlo theorist.
Calcineurin Inhibitor–Induced Nephrotoxicity and Renal Expression of P-glycoprotein

Study Objective. To evaluate immunohistochemistry staining patterns for P-glycoprotein (P-gp) and a marker of early apoptosis (active caspase-3) in renal biopsy specimens obtained from solid organ transplant recipients with nephrotoxicity and those from a control group. Design. Retrospective analysis of pathology specimens and medical records. Setting. Medical university. Subjects. Twenty-nine solid organ transplant recipients with nephrotoxicity and 32 control patients. Measurements and Main Results. Medical records were reviewed for patient demographics, clinical laboratory results, and prescribed drugs. Immunohistochemistry techniques using primary antibodies to P-gp and active caspase-3 were performed to evaluate staining patterns of these proteins in the kidney specimens. Differences in measures of interest between groups were compared with the Fisher exact test for categoric data and Wilcoxon rank sum test for continuous data. Logistic and linear modeling were used to evaluate difference in measures of P-gp and active caspase-3 between groups while controlling for confounders. Immunohistochemistry confirmed the presence of P-gp in the renal tubules (apical and basal membranes and cytoplasm). Intensity of P-gp staining (score range 0–4) was reduced in renal specimens of transplant recipients with nephrotoxicity compared with the control specimens (mean ± SD intensity scores 3.2 ± 0.7 vs 3.8 ± 0.4, p=0.0002). Neither P-gp–inducing nor P-gp–inhibiting drugs predicted expression of P-gp in the renal specimens of either group. The extent of tubular staining (score range 1–4) for the apoptosis marker, active caspase-3, was less in the nephrotoxicity group than in the control group (mean ± SD extent scores 1.7 ± 0.6 vs 2.8 ± 0.5, p=0.0003). Conclusion. P-glycoprotein expression was less pronounced in renal biopsy specimens with calcineurin inhibitor–induced nephrotoxicity compared with the nonnephrotoxic control specimens. Reduced P-gp expression was evident even when the analysis controlled for factors such as renal function, age, sex, race, diabetes mellitus, level of proteinuria, or prescribed therapy with P-gp inducers or inhibitors. Interpretation of the results from active caspase-3 staining requires further study.
Acousto-optic Spectrometer For Radio Astronomy

One of the most significant developments in radio astronomy has been the recent discovery of over 50 different molecules in the interstellar medium. These observations have changed our picture of the distribution of mass in the galaxy, altered our understanding of the process of star formation, and has also opened up a new and lively field of interstellar chemistry. This achievement was made possible not only by the development of sensitive heterodyne receivers (front-end))in the centimeter and millimeter range, but also by the construction of sensitive RF spectrometers (back-end) which enabled the spectral lines of molecules to be detected and identified. Traditionally spectrometers have been constructed as banks of discrete adjacently tuned RF filters or as digital auto-correlators. However, a new technique combining acoustic bending of a collimated coherent light beam by a Bragg cell followed by detection by a sensitive array of photodetectors (thus forming a RF acousto-optic spectrometer (AOS) promises to have distinct advantages over older spectrometer technology. An AOS has wide bandwidth, large number of channels, high resolution, and is compact, light weight, and energy efficient. These factors become very important as heterodyne receivers are developed into the submillimeter, far infrared, and 10 micronspectral ranges and as more observations are performed from remote, airborne, or spaceborne platforms. We give a short description and report of existing AOS backends in Australia and Japan but will concentrate on our recent construction of a proto-type AOS at Goddard Space Flight Center. The GSFC AOS uses a discrete bulk acoustic wave Itek Bragg Cell, 5 mW Helium-Neon laser, and a 1024 element Reticon CCPD array. The analog signals from the photodiode array are digitized, added and stored in a very high-speed custom built multiplexer board which allows us to perform synchronous detection of weak signals. The experiment is controlled and the data is displayed and stored with an LSI-11 microcomputer system with dual floppy disks. We will report the performance of the GSFC AOS obtained from our initial tests. We also will give a description of an integrated SAW Bragg cell which will miniaturize a complete AOS system into a 1x3 inch package.
SRLG-aware topology aggregation for survivable multi-domain optical networks

In multi-domain optical networks, due to confidentiality and management considerations, it may be infeasible to exchange complete domain state information among domains. Topology aggregation (TA) is a widely adopted technique for aggregating a domain's detailed topology into simpler aggregated topology with limited information. In order to generate an abstracted topology that is more survivable against failures, the TA approach may also consider the presence of shared risk link groups (SRLGs), each of which defines a set of links that may fail simultaneously. We propose SRLG-aware topology aggregation approaches that can help to find a pair of inter-domain paths with a minimum set of common SRLGs. We find that constructing an aggregated topology while taking into account the SRLG distribution can help in developing a more survivable aggregated multi-domain network. Moreover, exchanging SRLG information prior to constructing the TA further increases the survivability of the aggregated topology. The performance of various TA schemes, such as single node, star, and full mesh, is also investigated.
T-Tail Transport Empennage Loads in Continuous Atmospheric Turbulence

Empennage loads on T tail transport determined for combined vertical and lateral gust loads using real time analog-digital computer simulation
Differential Involvement of Caspases in Hydroquinone-Induced Apoptosis in Human Leukemic HL-60 and Jurkat Cells

The benzene metabolite hydroquinone (HQ) is postulated to exert its myelotoxicity by bioactivation to reactive quinone derivatives in myeloperoxidase (MPO)-containing cells. In this study, the role of caspases in hydroquinone-induced apoptosis in MPO-rich HL-60 promyelocytic leukemia and MPO-deficient Jurkat T-lymphoblastic leukemia cells was investigated. HQ-induced apoptosis in both cell types was accompanied by phosphatidylserine (PS) exposure, caspases-3/-7 activation, PARP cleavage, DNA fragmentation, and ultrastructural changes as assessed by electron microscopy. In HL-60 cells, the general caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp fluoromethyl ketone (Z-VAD.FMK) blocked activation of caspases-3/-7, cleavage of PARP, and DNA, but PS externalization and cytoplasmic changes were not significantly affected. In marked contrast, all features of apoptosis were completely inhibited by Z-VAD.FMK in HQ-treated Jurkat cells. These data provide evidence for Z-VAD.FMK-insensitive and caspases-3/-7-independent pathway(s) in the externalization of PS and cytoplasmic changes during HQ-induced apoptosis in HL-60 cells. In contrast, in Jurkat cells, all of these changes required caspase activation. The ability of HQ to induce equivalent apoptosis in both MPO-deficient Jurkat cells and MPO-rich HL-60 cells demonstrates that MPO-catalyzed bioactivation of HQ is not a prerequisite for toxicity. The differential mechanisms of apoptosis in HL-60 and Jurkat T cells may reflect the MPO activity of these cells and, as a result, the amount of reactive BQ and other metabolites that are generated.
A simple, low power, self referenced technique for complete characterization of optical frequency combs and arbitrary waveforms

We demonstrate a simple scheme which uses only an intensity modulator and an OSA to achieve low-power (∼100nW, 10aJ/pulse at 10GHz), self-referenced, amplitude and phase characterization of optical frequency combs and 100% duty factor arbitrary waveforms.
How Do Public Organizations Learn? Bridging Cultural and Structural Perspectives

How do public organizations learn? The organizational learning literature suggests distinct cultural and structural routes to learning. However, such categorizations oversimplify. Leaders seeking to foster learning should recognize that most relevant organizational variables combine structural and cultural aspects, which are mutually dependent on one another. The strongest influences are the existence of work groups that are purpose driven and incorporate the views of all members, including dissenting views. Such learning forums can be fostered through formal requirements, but they need appropriate cultural characteristics to succeed. Mission orientation, decision authority, information systems, and resource adequacy are also positively related to improved organizational learning.
The human telomere.

An ultimate goal of human genetics is the generation of a complete physical and ''functional'' map of the human genome. Twenty-five percent of human DNA, however, consists of repetitive DNA sequences. These repetitive DNA sequences are thought to arise by many mechanisms, from direct sequence amplification by the unequal recombination of homologous DNA regions to the reverse flow of genetic information. A general outline of the chromosomal organization of these repetitive sequences will be discussed. Our working hypothesis is that certain classes of human repetitive DNA sequences ''encode'' the information necessary for defining long-range genomic structure. Evidence will be presented that the first goal of this research, the identification and cloning of the human telomere, has been achieved. A human repetitive DNA library was constructed from randomly sheared, reassociated, and oligo(G/center dot/C)-tailed DNA, a method that minimizes the potential loss of sequences devoid of a given restriction enzyme site. Sequences too large to clone efficiently in cosmid or /lambda/ vectors, such as centromeric repeats, or telomeric sequences with an end incompatible for cloning, should be present in this library. In order to isolate highly conserved repetitive DNA sequences, this library was screened with radiolabeled hamster Cot50 repetitive DNA. Two clones, more » containing tandem arrays of the sequence (TTAGGG), were isolated by this method. 30 refs., 1 fig., 2 tabs. « less
Chemical methods to interrogate bacterial quorum sensing pathways

Bacteria frequently manifest distinct phenotypes as a function of cell density in a phenomenon known as quorum sensing (QS). This intercellular signalling process is mediated by “chemical languages” comprised of low-molecular weight signals, known as autoinducers, and their cognate receptor proteins. As many of the phenotypes regulated by QS can have a significant impact on the success of pathogenic or mutualistic prokaryotic–eukaryotic interactions, there is considerable interest in methods to probe and modulate QS pathways with temporal and spatial control. Such methods would be valuable for both basic research in bacterial ecology and in practical medicinal, agricultural, and industrial applications. Toward this goal, considerable recent research has been focused on the development of chemical approaches to study bacterial QS pathways. In this Perspective, we provide an overview of the use of chemical probes and techniques in QS research. Specifically, we focus on: (1) combinatorial approaches for the discovery of small molecule QS modulators, (2) affinity chromatography for the isolation of QS receptors, (3) reactive and fluorescent probes for QS receptors, (4) antibodies as quorum “quenchers,” (5) abiotic polymeric “sinks” and “pools” for QS signals, and (6) the electrochemical sensing of QS signals. The application of such chemical methods can offer unique advantages for both elucidating and manipulating QS pathways in culture and under native conditions.
Riesz potentials, Bessel potentials and fractional derivatives on Triebel–Lizorkin spaces for the Gaussian measure

Abstract In [3] the boundedness properties of Riesz potentials, Bessel potentials and fractional derivatives were studied in detail on Gaussian Besov–Lipschitz spaces B p , q α ( γ d ) . In this paper we will continue our study proving the boundedness of those operators on Gaussian Triebel–Lizorkin spaces F p , q α ( γ d ) . Also, these results can be extended to the case of Laguerre or Jacobi expansions and even further to the general framework of diffusions semigroups.
Suppression of choroidal neovascularization through inhibition of APE1/Ref-1 redox activity

Purpose The redox function of APE1/Ref-1 is a key regulator in pathological angiogenesis, such as retinal neovascularization and tumor growth. In this study, we examined whether inhibition of APE1/Ref-1 redox function by a small molecule inhibitor E3330 suppresses experimental choroidal neovascularization (CNV) in vitro and in vivo. Methods Primate choroid endothelial cells (CECs) received treatment of 0 to 100 μM E3330 alone or cotreatment of E3330 and 500 μg/mL anti-VEGF antibody bevacizumab. Choroid endothelial cell angiogenic function was examined by cell proliferation, migration, and tube formation assays. The effects of E3330 on NF-κB and STAT3 signaling pathways were determined by reporter gene assay, Western blot, and ELISA. Laser-induced CNV mouse model was used to test the effects of E3330 in vivo. Potential toxicity of E3330 was evaluated by TUNEL assay. Results The E3330 of 25 to 100 μM dose-dependently suppressed CEC proliferation, migration, and tube formation, in the absence of noticeable cell toxicity. Lower doses of E3330 (10-20 μM) reduced the transcriptional activity of NF-κB and STAT3 without affecting protein phosphorylation of both molecules. At the same time, E3330 downregulated MCP-1 production in CECs. The antiangiogenic effect of E3330 was comparable and additive to bevacizumab. The E3330 effectively attenuated the progression of laser-induced CNV in mice after a single intravitreal injection. Conclusions The APE1/Ref-1 redox function regulates multiple transcription factors and inflammatory molecules, and is essential for CEC angiogenesis. Specific inhibition of APE1/Ref-1 redox function with E3330 may represent a promising novel treatment for wet AMD.
Use of adjuvant radiation therapy in the management of acinar cell carcinoma of the pancreas: results from the Survival, Epidemiology, and End Results database

Acinar cell carcinoma (ACC) is an extremely rare cancer of the pancreas, accounting for less than 1 % of non-endocrine pancreatic tumors. The role for adjuvant radiation therapy (RT) in the management of this disease is unknown. The Survival, Epidemiology, and End Results 18 database, November 2012 submission, was queried for ACC of the pancreas reported between the years of 1998 and 2010. Baseline characteristics were compared with the chi-squared test. Overall survival (OS) and cause-specific survival (CSS) were estimated using the Kaplan–Meier method. Cox proportional hazard modeling was performed for multivariate analysis of factors associated with OS and CSS. Analyses were performed using SPSS, version 20. Two hundred nineteen patients with acinar cell carcinoma were identified. Median follow-up was 11 months. Median patient age was 66 (range 4–92). One hundred fourteen patients (52.1 %) had locoregional disease, while 105 patients (47.9 %) had metastatic disease at diagnosis. Median OS for all patients was 14 months (95 % confidence interval (CI) 9.24–18.77 months), and median CSS was 17 months (95 % CI 10.37–23.63 months). For patients with non-metastatic disease, median OS was 38 months (95 % CI 28.43–47.57). Among patients with non-metastatic disease, the use of adjuvant radiation was associated with increased median OS (56 months [95 % CI 21.67–90.33]), compared to patients not treated with radiation (27 months [95 % CI 4.06–49.94]), p = 0.046. Use of adjuvant radiation was associated with increased cause-specific survival (66 vs. 40 months), but this was not statistically significant (p = 0.104). On multivariate analysis, use of surgery and adjuvant radiation were both associated with improved OS for patients with non-metastatic disease (hazard ratio (HR) 0.517, p = 0.034 and HR 0.423, p = 0.009, respectively). Both surgery and radiation were associated with non-statistically significant improvement in ACC cause-specific survival, HR = 0.606 (95 % CI = 0.314–1.170), p = 0.136 and HR = 0.501 (95 % CI = 0.249–1.009), p = 0.053, respectively. Surgical resection with curative intent followed by adjuvant RT is associated with excellent long-term overall survival in patients with non-metastatic local-regional acinar cell carcinoma of the pancreas.
H–spaces, loop spaces and the space of positive scalar curvature metrics on the sphere

For dimensions n 3, we show that the space Riem C .S n / of metrics of positive scalar curvature on the sphere S n is homotopy equivalent to a subspace of itself which takes the form of an H‐space with a homotopy commutative, homotopy associative product operation. This product operation is based on the connected sum construction. We then exhibit an action on this subspace of the operad obtained by applying the bar construction to the little n‐disks operad. Using results of Boardman, Vogt and May we show that this implies, when n 3, that the path component of Riem C .S n / containing the round metric is weakly homotopy equivalent to an n‐fold loop space. Furthermore, we show that when nD 3 or n 5, the space Riem C .S n / is weakly homotopy equivalent to an n‐fold loop space provided a conjecture of Botvinnik concerning positive scalar curvature concordance is resolved in the affirmative. 53C99; 55S99
Simulation of Thermal Transport in Open-Cell Metal Foams: Effect of Periodic Unit-Cell Structure

Direct simulation of thermal transport in open-cell metal foams is conducted using different periodic unit-cell geometries. The periodic unit-cell structures are constructed by assuming the pore space to be spherical and subtracting the pore space from a unit cube of the metal. Different types of packing arrangement for spheres are considered—body centered cubic, face centered cubic, and the A15 lattice (similar to a Weaire-Phelan unit cell)—which give rise to different foam structures. Effective thermal conductivity, pressure drop, and Nusselt number are computed by imposing periodic boundary conditions for aluminum foams saturated with air or water. The computed values compare well with existing experimental measurements and semiempirical models for porosities greater than 80%. The effect of different foam packing arrangements on the computed thermal and fluid flow characteristics is discussed. The capabilities and limitations of the present approach are identified. DOI: 10.1115/1.2789718
General cosmological constraints on the masses of stable neutrinos and other “inos”

The arguments favoring non-baryonic dark matter are summarized. In particular, if the cosmological density parameter Ω≳ 0.15, the universe must be dominated by non-baryonic matter. General cosmological constraints, independent of detailed galaxy formation scenarios, are presented on the masses of stable neutrinos and other “inos,” where ino represents any candidate particle for the dark matter in the universe: (i) The requirement that the total mass density not exceed Ω ≲ 4 restricts neutrinos to two mass ranges, ∑mv ≲ 400 eV and mv ≳ 1 GeV. (ii) From age of the universe arguments, tighter constraints on the lower of the two mass ranges become ∑mv ≲ 25 eV (∑mino ≲ 400 eV) or ∑mv ≲ 100 eV (∑mino ≲ 2 keV) depending on age technique used. An actual determination of a neutrino mass puts an upper limit on the age of the universe, and in a neutrino-dominated universe Ω = 1 is only possible for ∑mv ≳ 25 eV. (iii) From phase-space density arguments, a necessary (but not sufficient) condition for the clustering of neutrinos on large scales is that mv ≳ 3 eV. (iv) For the formation of large-scale structure, the maximum neutrino Jeans mass should not exceed supercluster scales and therefore mv ≳ 10 eV. Three neutrinos of equal mass can be excluded if one uses globular cluster determinations of the age in (ii) above. (v) If the formation of large-scale structure requires damping of small scales and hence a minimum value of the maximum neutrino Jeans mass, mino ≲ 200 eV for dominant particles. In a universe with Ω ⋍ 1 and photon temperature Tγ0 = 2.7 K, this also leads to the constraint that decoupling temperature if TD of the dominant ino is TD ≲ 100 MeV. (vi) Big-bang nucleosynthesis restricts the number of neutrino species to at most four, probably only three. These arguments are then synthesized to show that all of the independent constraints can only be simultaneously met in a “best-fit” model with 10 eV ≲ mv ≲ 25 eV for the most massive neutrino eigenstate. Independently of galaxy formation arguments and with only the extremely conservative age limit, it can still be said that 3 eV ≲ mv ≲ 100 eV. Note also that if constraint (v) is valid then the dominant ino acts in every way like a massive neutrino and thus if (vi) also holds, it probably is a massive neutrino. Differences in adiabatic and isothermal fluctuation models are discussed; in particular the GUTs preferred adiabatic mode is only consistent with limits on 3 K anisotropies if non-baryonic matter dominates. Problems on small-scales with galaxy correlation studies and equilibrium time scales in a neutrino-dominated universe with adiabatic fluctuations are discussed. For Ω ∼ 0.2–0.6 cold matter such as axions or GeV mass inos could be dominant matter, but in an Ω ⋍ 1 universe these as well as keV mass “inos” are not optimal for the dominant matter and the best fit is a neutrino of mass mv ⋍ 25 eV.
CFT's from Calabi–Yau four-folds

Abstract We consider F/M/Type IIA theory compactified to four, three, or two dimensions on a Calabi–Yau four-fold, and study the behavior near an isolated singularity in the presence of appropriate fluxes and branes. We analyze the vacuum and soliton structure of these models, and show that near an isolated singularity, one often generates massless chiral superfields and a superpotential, and in many instances in two or three dimensions one obtains nontrivial superconformal field theories. In the case of two dimensions, we identify some of these theories with certain Kazama–Suzuki coset models, such as the N =2 minimal models.
The INTEL® 8087 numeric data processor

The INTEL® 8087 is a high performance general purpose numeric data processor. It is used with the INTEL® 8086, or the INTEL® 8088, microprocessors to extend their instruction sets with over 100 instructions (not counting addressing mode). The 8087 has all of the 8086 addressing modes and through a coprocessing interface is able to execute numeric instructions concurrently with the 8086 (or 8088). The high performance overlapped execution is transparent to the user who sees the 8087 simply as an extension of the 8086 (8088). Furthermore, the 8087 is the only chip that must be added to an 8086-based system to provide numerics capability with a performance enhancement over software of more than 100. In addition to high performance, great care was taken to ensure that the 8087 could be used in any application involving numbers---including commercial calculations. This required an unprecedented level of accuracy and reliability to be built into the processor. The intent was to greatly simplify the production of high performance but reliable numeric software.
Ultrasound-assisted synthesis of carbon materials

In this Perspective, the use of ultrasound in the synthesis and modification of carbon materials is surveyed. Ultrasound is a common laboratory tool used to nebulize solutions into fine mists, emulsify mixtures, and drive chemical reactions. Given society’s continued use of carbon materials (e.g., carbon black and activated carbon) as pigments, adsorbents, and composite components as well as the exciting new applications being explored for carbon nanotubes, graphene, and meso- and macroporous carbons, the use of ultrasound in the synthesis and modification of carbon materials is of general interest. Here, carbon materials prepared by both ultrasonic spray pyrolysis and high intensity ultrasound will be discussed, with the properties and applications enabled by their preparation highlighted within the individual examples. This article is concluded with some personal perspectives on the directions toward which future research may be aimed.