cssi/SciSciGPT-SciSciNet huggingface dataset:
Preparation of interconnected poly(ε-caprolactone) porous scaffolds by a combination of polymer and salt particulate leaching

Abstract This paper examines a new technique for the preparation of porous scaffolds by combining selective polymer leaching in a co-continuous blend and salt particulate leaching. In the first step of this technique, a co-continuous blend of two biodegradable polymers, poly(e-caprolactone) (PCL) and polyethylene oxide (PEO), and a certain amount of sodium chloride salt particles are melt blended using a twin screw extruder. Subsequently, extraction of the continuous PEO and mineral salts using water as a selective solvent yields a highly porous PCL scaffold with fully interconnected pores. Since, the salt particles and the co-continuous polymer blend morphology lead to very different pore sizes, a particular feature of this technique is the creation of a bimodal pore size distribution. Scanning electron microscopy, mercury intrusion porosimetry and laser diffraction particle size analysis were carried out to characterize the pore morphology. The prepared scaffolds have relatively homogeneous pore structure throughout the matrix and the porosity can be controlled between 75% and about 88% by altering the initial volume fraction of salt particles and to a lesser extent by changing the PCL/PEO composition ratio. Compared to the conventional salt leaching technique and to its different variants, the proposed process allows a better interconnection between the large pores left by the salt leaching and a fully interconnected porous structure resulting from the selective polymer leaching. The average compressive modulus of the different porous scaffolds was found to decrease from 5.2 MPa to about 1 MPa with increasing porosity, according to a power–law relationship. Since, the blending and molding of the scaffold (prior to leaching) can be made using conventional polymer processing equipment, this process seems very promising for a large scale production of porous scaffold of many sizes and in an economic way.
MRI of diffuse liver disease: The common and uncommon etiologies

Diffuse liver disease, including all causes of chronic liver disease, affects tens of millions of people worldwide. There is a growing need for diagnostic evaluation as treatments become more readily available, particularly for viral liver disease. Magnetic resonance imaging (MRI) provides unique capabilities for noninvasive characterization of liver tissue that rival or surpass the diagnostic utility of liver biopsies. There has been incremental improvement in the use of standardized MRI sequences, acquired before and after administration of contrast for the evaluation of diffuse liver disease, and this includes study of the liver parenchyma and blood supply. More recent developments have led to methods for quantifying important liver metabolites, including fat and iron, and liver fibrosis, which is the hallmark for chronic liver disease. In this study, we review the MRI techniques and diagnostic features associated with common and uncommon etiologies of diffuse liver diseases, including processes that lead to abnormal perfusion (e.g. Budd-Chiari syndrome, congestive hepatomegaly), deposition diseases (e.g. fatty liver, hemochromatosis, Wilson's disease), and abnormalities that are related to inflammation and fibrosis (e.g. primary sclerosing cholangitis, sarcoidosis).
Computer-controlled xenon ion engine operation

The development and testing of a computer control system for a 5-kW xenon ion engine is described. The computer system controls all aspects of the engine operation including startup, steady-state operation, throttling and shutdown of the engine and neutralizer, as well as operation of the valves in the propellant storage and distribution system. The most important engine control algorithms are described. These control algorithms provide flexibility in the operation and throttling of ion engines that has never before been possible. This flexibility is made possible in large part through the use of flow controllers that maintain the total flow rate of propellant into the engine at the proper level. Data demonstrating the throttle capabilities of the engine and control system are presented.
Proportional counters as low energy photon detectors

We investigated the response of an argon-methane proportional counter to monochromatic X-rays in the range 99 to 277 eV. The apparent nonlinearities in mean pulse height as a function of photon energy and the detailed shape of the pulse height distribution for each energy can be predicted quite precisely using the extensive atomic data available for argon. Based on this understanding, we propose a semi-empirical system for using a limited amount of calibration data to predict the full response of counters employing less well-characterized gases. Such accurate models of proportional counters are required to maximize the spectral information that can be derived from observed pulse height distributions.
Regulation of clathrin adaptor function in endocytosis: novel role for the SAM domain

During clathrin-mediated endocytosis, adaptor proteins play central roles in coordinating the assembly of clathrin coats and cargo selection. Here we characterize the binding of the yeast endocytic adaptor Sla1p to clathrin through a variant clathrin-binding motif that is negatively regulated by the Sla1p SHD2 domain. The crystal structure of SHD2 identifies the domain as a sterile α-motif (SAM) domain and shows a propensity to oligomerize. By co-immunoprecipitation, Sla1p binds to clathrin and self-associates in vivo. Mutations in the clathrin-binding motif that abolish clathrin binding and structure-based mutations in SHD2 that impede self-association result in endocytosis defects and altered dynamics of Sla1p assembly at the sites of endocytosis. These results define a novel mechanism for negative regulation of clathrin binding by an adaptor and suggest a role for SAM domains in clathrin-mediated endocytosis.
Petrophysical Description of Tight Gas Sands

Summary This paper discusses petrophysical description of tight gas sands formations. We analyze correlations between velocity, permeability, and porosity in three tight sand reservoirs. Flow zone indicator and effective specific surface area methods are introduced to analyze the relations between these properties. Correlations between velocity, permeability, and porosity of clean tight sands are shown to be well characterized after binning the data into zones with distinct effective specific surface or flow zones.
Nonlinear optical properties of conducting polyaniline and polyaniline–Ag composite thin films

Abstract The intensity dependent refractive indices of polyaniline and polyaniline–silver nanocomposites are measured. While the material are not good candidates for all-optical switching, they do exhibit reversible processes of saturable and reverse saturable absorption at the same wavelength, a trait that makes them suitable materials for optical pulse compression and limiting.
The versatile coordination chemistry of tricyanoethenolate, [(NC)2C=C(CN)O]−

Abstract The reaction of meso-tetrakis (4-dimethoxyphenyl) porphinatomanganese(II), MnTPOMeP, with TCNE (TCNE = tetracyanoethylene) leads to the formation of [MnTPOMeP]+ [TCNE]− and [MnTPOMeP]+[OC(CN)C(CN)2]−. The single-crystal X-ray structures of the latter as well as [Cu(bipy)2Cl]+ [OC(CN)C(CN)2]− were determined. The former has a disordered [OC(CN)C(CN)2]− bridging via C and O between a pair of MnIII sites, whereas the latter has an isolated [OC(CN)C(CN)2]− unbound to CuII. The IR characterization for μ2-C,O bound [OC(CN)C(CN)2]− is at 2219m and 2196s (νCN) cm−1 and at 1558s (νCO) cm−1 while for unbound [OC(CN)C(CN)2]− it is at 2210m, 2203m, 2181m (νCN) cm−1 and at 1583s (νCO) cm−1.
MACRO- AND MICROSCOPIC APPROACHES TO PLANE STRAIN DEFORMATION STATES OF FACE-CENTERED CUBIC METALS UNDER WEDGE INDENTATION

Face-centered cubic (FCC) metals show active slip under indentation loading. In this work, both macro- and microscopic models are proposed to analyze the deformation behavior of face-centered-cubic (FCC) single crystals under wedge indentation. In the part of macroscopic approach, stress distribution and anisotropic yielding were investigated. Load-displacement relation was obtained to reveal the mechanical responses of the crystals. In the microscopic approach section, an indention induced lattice rotation zone was identified and the deformation behavior was analyzed using the single crystal plasticity theory. The crystal lattice rotation experimental results and slip line trace observations validate the analytical predictions.
Role of plasma, platelets, and endothelial cells in tumor metastasis

This review studies interactions of tumor cells with a particular host system which is normally responsible for hemostasis and the physiological integrity of the blood vessel luminal surface. With malignancy components of this system are frequently activated, producing abnormalities of blood coagulation, increased platelet responses, and conditions favoring tumor growth and metastasis. Activation of the clotting cascade is mediated by tumor and macrophage procoagulants, acting via Factor X or VII. Thrombin and fibrin are formed. Thrombin also interacts with platelets and the endothelium, potentiating or decreasing coagulation. Generation of thrombin or other tumor mechanisms activate platelets, leading to direct aggregation or secretion of ADP, serotonin, and/or intermediates of the arachidonate metabolism. Vascular lesions caused by tumor attack, platelet secretion, or exogenous agents promoting metastasis may also activate the hemostatic system. It is not yet fully understood how activation of the clotting system, including platelets, contributes to metastasis. Secretion of platelet products appears, however, to be heavily involved. Based on putative mechanisms of action, anticoagulants, platelet inhibitors, thrombocytopenic or vascular repairing agents have been used to control tumor spread. Results depended on the agent and experimental model of metastasis used. Except for coumarin, which was beneficial even against spontaneous metastases, other anticoagulants and platelet inhibitors, excluding perhaps Nafazatrom, gave equivocal results. Thrombocytopenic agents, However, were effective in every tumor system and with any experimental model of metastasis, indicating that platelets play a role in this process. Also consistent were the inhibitory effects of leech salivary gland extract (probably a vascular repairing agent) against lung tumor colonization promoted by ionizing radiation, cyclophosphamide, and cortisone.
Estimate of solid flow rate from pressure measurement in circulating fluidized bed

Abstract A method is described to estimate solid mass flow rate based on measurement of pressure drop in horizontal section of circulating fluid bed (CFB). A theoretical model was derived based on momentum balance equation and used to predict the solids flow rate. Several approaches for formulating such models are compared and contrasted. A correlation was developed that predicts the solids flow rate as a function of pressure drop measured in the horizontal section of piping leading from the top of the riser to the cyclone, often referred to as the cross-over. Model validation data was taken from literature data and from steady state, cold flow, CFB tests results of five granular materials with various sizes and densities in which the riser was operated in core-annular and dilute flow regimes. Experimental data were taken from a 0.20 m ID cross-over piping and compared to literature data generated in a 0.10 m ID cross-over pipe. The solids mass flow rate data were taken from statistically designed experiments over a wide range of Froude number U g 2 g D , 25 – 2 00 , load ratio G s ρ g U g , 0. 2 – 23 , Euler number 2 Δ P Horiz ρ g U g 2 ,2 – 5 0 , density ratio ρ p − ρ g ρ g , 6 0 – 2 000 , Reynolds number ρ g U g d p μ g , 6 0 – 16 00 , and Archimedes number ρ s − ρ g ρ g d p 3 μ g 2 , 29 – 95 00 . Several correlations were developed and tested to predict the solids mass flux based on measuring pressure drop in the horizontal section of CFB. It was found that load ratio G s ρ g U g is a linear function of the Euler number 2 Δ P Horiz ρ g U g 2 and that each of these expressions all worked quite well (R2 > 95%) for the data within the range of conditions from which the coefficients were estimated.
Comparing the spectroscopic and electrochemical properties of ruthenium and osmium complexes of the tridentate polyazine ligands 2,2′:6′,2″-terpyridine and 2,3,5,6-tetrakis(2-pyridyl)pyrazine

Abstract A number of osmium and ruthenium complexes of the tridentate ligands 2,2′:6′,2″-terpyridine (tpy) and 2,3,5,6-tetrakis(2-pyridyl)pyrazine (tpp) have been prepared and characterized by our laboratory. All these complexes possess metal based oxidations and ligand based reductions localized on each polyazine ligand. Polymetallic complexes bridged by the tpp ligand exhibit two sequential tpp based reductions prior to the reduction of other polyazine ligands in these complexes. The spectroscopy of these complexes is dominated by ligand based π-π ∗ transitions in the ultraviolet and MLCT (metal-to-ligand charge transfer) bands terminating on each polyzine ligand in the visible. For the complexes reported herein the lowest lying optical transitionis a M → BL CT band. For most of the complexes reported, occupation of this excited state gives rise to an observable emission at room temperature. For ruthenium complexes of these tridentate ligands, the presence of a low-lying LF state shortens the excited state lifetimes of these chromophores. This gives rise to ruthenium complexes that display shorter excited state lifetimes than the analogous osmium based systems. Incorporation of tpp based chromophores into polymetallic frameworks leads to the production of bimetallic species with long-lived excited states, ∼ 100 ns at room temperature. This makes these chromophores good candidates for the development of stereochemically defined supramolecular complexes. It is possible to measure an electrochemical HOMO-LUMO energy gap and a correlation between this electrochemically measured energy gap and the spectroscopic energy associated with this HOMO→LUMO transition are reported herein (HOMO== highest occupied molecular orbital, LUMO = lowest unoccupied molecular orbital).
HCN Synthesis by Ammoxidation of Methane and Ethane on Platinum Monoliths

We have examined HCN synthesis by the ammoxidation of CH4, C2H6, and CH4/C2H6 mixtures in air or O2 at atmospheric pressure on α-Al2O3 foam monoliths coated with 1−10 wt % Pt and on Pt−10% Rh gauzes. The HCN reaction system was found to be highly sensitive to the catalyst microstructure because we observed activation and differences in performance on catalysts with different support materials. For CH4 ammoxidation on Pt monoliths we observe HCN yields >63% based on CH4 and NH3 fed which is comparable to yields obtained on commercially used Pt−10% Rh gauzes (∼65%). With C2H6 rather than CH4, we achieve HCN yields of ∼42% (carbon and nitrogen basis). We also examined CH4/C2H6 mixtures (at fixed C/N and (C + N)/O2) for HCN synthesis. HCN yields were found to decrease by 5−7% with increasing C2H6 in the feed hydrocarbon mixture (up to 14%). Results for experiments with Pt−10%Rh gauzes used commercially are shown in all cases to allow comparisons with Pt monoliths. C2H6 ammoxidation on Pt monoliths and gauzes ...
A test of the “;ceiling effect”; hypothesis of positive contrast

Seventy-two rats were given 0, 5, 10, or 15 small rewarded trials prior to being shifted to large reward for the remainder of 45 trials. Each of the groups which experienced an upward shift in reward magnitude rapidly approximated the performance of a consistently large rewarded control group, and in no case was a positive contrast effect observed. The performance curves for all the groups remained interlaced for a rather protracted period of asymptotic training. The results were discussed in terms of their relevance to the “;ceiling effect”; hypothesis of the absence of positive contrast.
Effects of methylphenidate on weight gain and food intake in hypothalamic obesity.

For patients with a craniopharyngioma (CP), treatment of hypothalamic obesity (HO) and hyperphagia following resection and/or radiotherapy is extremely difficult and few reports have been published on potential drug therapies. Psychomotor stimulant methylphenidate (MPH) has been reported to inhibit food intake. In this paper, we report reduction of body mass index (BMI) and appetite in an adolescent CP patient suffering from HO. We then tested the ability of MPH to attenuate the food intake (FI) and body weight (BW) gain in a rat model consistent with the neuroanatomical and metabolic disturbances commonly observed in obese CP patients. Specifically, we used a novel electrolytically generated combined medial hypothalamic lesion (CMHL) affecting the arcuate nucleus (ARC), ventromedial hypothalamic nucleus (VMN) and dorsomedial hypothalamic nucleus (DMN) to induce hyperphagia, rapid weight gain, and adiposity. Both CMHL and control animals (n=7 per group) were administered either methylphenidate HCl (MPH; 20 mg•kg-1•day-1) or saline for four days in a crossover design experiment 28 weeks post surgery. A significant decrease in percent baseline FI (CMHL -23%, p=0.008; control -20%, p=0.002) and percent change in BW (CMHL -1.97%/4 days, p=0.011; control -1.75%/4 days, p=0.003) was observed during MPH treatment as compared to saline. Conclusion: This study shows MPH treatment of severely obese CMHL rats resulted in significantly reduced FI and BW loss.
Microvascular function and ageing L-arginine, tetrahydrobiopterin and the search for the fountain of vascular youth.

Cardiovascular disease remains the most salient killer in the United States and ageing is a primary risk factor. With advancing age, there is pervasive macrovascular and microvascular dysfunction that manifests as stiffening of central elastic arteries, thickening of intimal–medial layers of the vascular wall, and diminished peripheral conduit artery/resistance artery vasodilatory capacity. Reduced endothelium-dependent vasodilatation has been shown in several prospective studies to be an independent predictor of adverse cardiovascular events. In the healthy vasculature, nitric oxide (NO) is released from endothelial cells in response to laminar shear stress and causes vasodilatation. In addition to its vasodilatory properties, NO is antiatherogenic: it inhibits platelet aggregation/adhesion, smooth muscle cell proliferation and lipid oxidation. Depletion of NO has been linked to several pathologies including atherosclerosis and hypertension. Understanding the mechanistic aspects of NO bioavailability, and loss thereof with ageing, has significant clinical relevance. Synthesizing NO requires a precise admixture of substrate and cofactors. Unidirectional laminar shear stress activates endothelial nitric oxide synthase (eNOS) via phosphorylation. l-Arginine is hydroxylated to N-hydroxy-l-arginine and then further oxidized to NO and l-citrulline. NO diffuses into smooth muscle cells, activates guanylate cyclase and induces cyclic GMP-mediated smooth muscle relaxation. Other substrate and cofactors required for this reaction include oxygen, NADPH, flavin, heme and tetrahydrobiopterin (BH4). Altering any one of these variables with ageing may set the reaction awry and attenuate vasodilatation. In an article recently published in The Journal of Physiology, Delp and associates examined several potential mechanisms that may contribute to reduced microvascular vasodilatory capacity with ageing (Delp et al. 2008). Delp et al. harvested arterioles from the soleus muscles of young and old rats and exposed them to graded increases in intraluminal flow in the absence of changes in intraluminal pressure. Results revealed that arterioles from old rats exhibited a 52% reduction in flow-mediated dilatation (FMD) compared to arterioles from young rats. Vessel dilatation was also assessed following administration of the NO donor sodium nitropruside (SNP). There were no group differences in SNP-mediated dilatation suggesting similar endothelial-independent vasodilatation in arterioles from young and old rats. Confirming that the age-associated difference in microvascular vasodilatation was endothelial dependent, Delp and associates proceeded to systematically and eloquently rule out several potential limiting factors regulating the NO signalling pathway.
EXPERIMENTAL HYPERSENSITIVITY IN THE RABBIT EFFECT OF INHIBITION OF ANTIBODY FORMATION BY X-RADIATION AND NITROGEN MUSTARDS ON THE HISTOLOGIC AND SEROLOGIC SEQUENCES, AND ON THE BEHAVIOR OF SERUM COMPLEMENT, FOLLOWING SINGLE LARGE INJECTIONS OF FOREIGN PROTEINS

X-radiation and nitrogen mustard administration inhibit the formation of precipitins for whole bovine serum and bovine serum gamma globulin in the rabbit. When specific antibody formation is inhibited by these agents, intravenous injection of a single large dose of bovine serum gamma globulin is not usually followed by the development of tissue lesions 9 to 11 days later, as occurs fairly regularly in control animals. A fall in titre of serum complement to very low levels for 3 to 5 days is closely correlated in time with the disappearance of antigen from the circulation following the intravenous injection of single large doses of bovine serum albumin and bovine serum gamma globulin. A rise in complement titre to normal levels occurs as antibodies appear in the serum. This sudden fall in complement titre is correlated with the development of characteristic lesions, and does not occur when antibody formation is inhibited. The data presented are interpreted as evidence in favor of the concept that the lesions are due to a reaction between antigen fixed in or on tissue cells and circulating antibody. The possible significance of serum complement in the pathogenesis of anaphylactic tissue lesions is discussed.
Isothermal titration calorimetry of metal ions binding to proteins: An overview of recent studies

Abstract Isothermal titration calorimetry (ITC) is a technique that is capable of quantifying the stoichiometry, equilibrium constants and thermodynamics of molecular binding events. Thus, important information about the interaction of metal ions with biological macromolecules can be obtained with ITC measurements. This review highlights many of the recent studies of metal ions binding to proteins that have used ITC to quantify the thermodynamics of metal–protein interactions.
Processing strategy moderates the cultivation effect

This study tested the hypothesis that processing strategy moderates the effect of television viewing on social perceptions (cultivation effect). One hundred twenty-two male and female students provided estimates of the prevalence of crime, occupations, affluence, and marital discord under one of three conditions. Some participants were induced to process heuristically (heuristic group) through instructions to provide their estimates spontaneously with little elaboration. Other participants were induced to process systematically (systematic group) through an accuracy motivation/task importance manipulation. A third (control) group received instructions to simply answer the questions. The results indicated that processing strategy moderated the cultivation effect such that cultivation effects were noted in the heuristic and control groups but not in the systematic group. These results are consistent with the notion that the cultivation effect can be explained in part as the result of heuristic processing through lack of source discounting, and they provide support for the heuristic processing model of cultivation effects.
Conductance Mapping of Proton Exchange Membranes by Current Sensing Atomic Force Microscopy

We show that proton conductance variation in Nafion membranes can be mapped using current sensing atomic force microscopy (CSAFM) to reveal and to characterize the heterogeneity in proton transport properties of the membranes. The distribution obtained by using a conventional CSAFM probe tip coated with a catalyst layer on a fresh Nafion membrane under a humid condition always displays a Gaussian-like shape. Such a feature can be explained in terms of the size of the contact area between a CSAFM tip and the membrane in comparison to the size of the tip apex. The conductance of individual proton channels and the density of the channels can be derived from the distribution. The averaged conductance and the density of proton channels derived are found to be consistent with that obtained in a recent simulation work based on the small-angle X-ray scattering (SAXS) data.
Solving combinatorial optimization problems using Karmakar's algorithm

We describe a cutting plane algorithm for solving combinatorial optimization problems. The primal projective standard-form variant of Karmarkar's algorithm for linear programming is applied to the duals of a sequence of linear programming relaxations of the combinatorial optimization problem.
A QUANTITATIVE CYTOGENETIC ANALYSIS OF AN INTERSECTIONAL HYBRID IN HELIANTHUS (COMPOSITAE).

From numerous pollinations of Helianthus laciniatus A. Gray sect. Ciliares by H. annuus L. sect. Helianthus (each with n = 17), a single hybrid was grown to maturity. The hybrid was vigorous but only 2.24% pollen-fertile compared to greater than 96% fertility in the parents. Backcrossing to the parental species was unsuccessful, so the possibility of gene flow between the species in nature is remote. Chromosome pairing in the parental plants was normal, but the hybrid was heterozygous for at least one paracentric inversion and numerous translocations. Chiasma frequencies of the parental genotypes were significantly different. The hybrid was significantly different from H. laciniatus and from the midparent value but not from H. annuus. These differences in chiasma frequencies were tested by the way chiasmata were allocated among the different meiotic configurations. Methods of converting multivalents to bivalent equivalents for comparison of chiasmata distribution among species and hybrids are demonstrated.
Response of the estuarine amphipod Gammarus daiberi to chlorinated power plant effluent

Abstract The amphipod Gammarus daiberi was subjected to plume drifts and laboratory exposures to chlorinated power plant cooling water effluent. Behavioral reactions to unchlorinated and chlorinated effluent were examined in an avoidance trough. During plant chlorination, the amphipods survived 1-h exposures to full-strength cooling water effluent (ΔT = 7.3–9.3 °C, 0.05 m l−1 total chlorine). Test groups of G. daiberi drifted through the discharge plume during chlorination displayed no increased immediate or latent mortalities. One-hour static bioassays revealed an initial TL50 value of 1.85 mg l−1 total chlorine, which decayed to 0.2–0.5 mg l−1 during the exposure period. At ambient temperatures of 26.4–26.6 °C, the amphipods avoided unchlorinated effluent at ΔT's > 3.3 °C. At lower ambient temperatures (15.3–15.7 °C), no avoidance was observed at a 7.1 °C ΔT. Chlorinated discharge water was avoided by G. daiberi at both ambient temperatures.
Analysis of a Basic Chemically Recuperated Gas Turbine Power Plant

This paper investigates a basic'' Chemically Recuperated Gas Turbine (a basic'' CRGT is defined here to be one without intercooling or reheat). The CRGT is of interest due to its potential for ultralow NO[sub x] emissions. A computer code has been developed to evaluate the performance characteristics (thermal efficiency and specific work) of the Basic CRGT, and to compare it to the steam-injected gas turbine (STIG), the combined cycle (CC) and the simple cycle gas turbine (SC) using consistent assumptions. The CRGT model includes a methane-steam reformer (MSR), which converts a methane-steam mixture into a hydrogen-rich fuel using the waste'' heat in the turbine exhaust. Models for the effects of turbine cooling air, variable specific heats, and the real gas effects of steam are included. The calculated results show that the Basic CRGT has a thermal efficiency higher than the STIG and simple cycles not quite as high as the combined cycle.
Atmospheric oxygen: isotopic composition and solubility fractionation.

Atmospheric oxygen has been found to be enriched in oxygen-18 by 23.5 ± 0.3 per mil relative to average ocean water (SMOW). Oxygen dissolved in seawater is further enriched in oxygen-18 by 0.85 per mil at 0°C. The temperature dependence of the solubility enrichment is given by e (per mil) = 0.85— 0.010 t (°C). This result is in good agreement with earlier measurements of the solubility effect in distilled water.
E-Business Models in B2B: Process Based Categorization and Analysis of B2B Models

The business models in business-to-business (B2B) e-commerce and their effectiveness have been a major topic of research in recent years. Due to the variety of existing models, it seems difficult to find a widely accepted categorization that can be analyzed and assessed. An in-depth study that provides a process-based approach to B2B e-commerce is presented and illustrated with examples from industry. A comparative examination of both the buy and the sell side based on a process-related approach provides extensive insights for further comparative research and evaluation of products, services, and models. Selling services and e-procurement using Web electronic-data interchange (EDI) as submodels are clarified using real-world examples. Problems and trends in the B2B area form the conclusion of the examination with suggestions for further research.
APPROXIMATING MAXIMUM 2-CNF SATISFIABILITY

A parallel approximation algorithm for the MAXIMUM 2-CNF SATISFIABILITY problem is presented. This algorithm runs in O(log2(n + |F|)) parallel time on a CREW PRAM machine using O(n + |F|) processors, where n is the number of variables and |F| is the number of clauses. Performance guarantees are considered for three slightly differing definitions of this problem.
Changed late Quaternary marine environments on Atlantic continental shelf and upper slope

Abstract About 2000 large sediment samples were collected during the early 1960s throughout the continental shelf off the Atlantic coast of the United States to establish and map sediment types including sediments relict from times of glacially low (and subsequently higher) sea levels. In about 510 of these samples we found fossil shells of mollusks remaining from environmental conditions different from those at present. Publications and collections by others contain about 70 additional samples having relict mollusks. Some of these shells indicate lower sea levels, others colder water, and still others warmer water than is now present. Radiocarbon measurements from earlier studies by us and others established the dates of colder water (late Pleistocene), and we made additional measurements to learn the dates of warmer water (about 1000 to 2000 yr B.P.). The results show reasonably enough that continental shelves are the sites of relict faunas as well as of sediments that indicate changed and complex environmental histories.
Magnetic field dependence of the dielectric constant in Cd1-x,MnxTe:In on approaching the insulator-to-metal transition

Abstract This study presents the frequency, temperature and magnetic field dependence of the capacitance in the dilute magnetic semiconductor Cd0.9Mn0.1Te: In near the insulator-to-metal transition. By exploiting the persistent photoconductivity effect or the large magnetic coupling between carriers and the localized (Mn2+) spins, it is possible to tune the transition in one sample either by optically changing the carrier concentration n or by applying a magnetic field H. The results indicate at least two contributions to the capacitance: a hopping term which is temperature and frequency dependent, and a term which varies only with n and H and is related to the polarizability of the bound charge carriers. This latter term is most evident at high frequencies and low temperatures and diverges as the transition is approached from the insulating side. The application of a magnetic field shifts the onset of the divergence to lower carrier concentrations, lending credence to earlier transport results which impl...
Combination Radioprotectors Maintain Proliferation Better than Single Agents by Decreasing Early Parathyroid Hormone-Related Protein Changes after Growth Plate Irradiation

Abstract Damron, T. A., Horton, J. A., Naqvi, A., Loomis, R. M., Margulies, B. S., Strauss, J. A., Farnum, C. E. and Spadaro, J. A. Combination Radioprotectors Maintain Proliferation Better than Single Agents by Decreasing Early Parathyroid Hormone-Related Protein Changes after Growth Plate Irradiation. Radiat. Res. 165, 350–358 (2006). Our hypothesis was that combinations of radioprotectors would be more effective than individual agents in minimizing the effects of radiation on the growth plate after single-fraction hind-limb irradiation of Sprague-Dawley rats. At 2 days postirradiation, the decrease in parathyroid hormone-related protein and parathyroid hormone receptor 1 expression in the irradiated growth plate transitional and hypertrophic zones was reversed in both of the combination groups but persisted in the groups treated with the individual drugs. By 2 weeks, positive findings unique to the combination-treatment animals included greater mean proliferation in the irradiated growth plate than on ...
Reconceptualizing Architectural Education for a More Diverse Future: Perceptions and Visions of Architectural Students

This article argues that the field of architecture must engage diversity in two senses of the word simultaneously: both in terms of its demographic composition and in terms of the substantive domain of architecture. Increasing the participation of women and minorities in the field should also mean increasing the substantive domain of the profession, and vice versa. We substantiate this argument within the realm of architectural education through a research study involving nearly 650 students at six different architecture schools. The purpose of the study was to investigate the ways in which both the content and the form of architectural education might impede or support the progress of women and minority students. In particular, we focus on three aspects of the “hidden curriculum”: studio pedagogy; social dynamics; and ideals and expectations. We find that women and members of some ethnic groups (particularly African-Americans and Latinos) do tend to experience the social dynamics and pedagogical practice...
Benign tertiary syphilis

Abstract Benign tertiary syphilis (BTS) includes all forms of symptomatic acquired syphilis occurring beyond the secondary and relapsing stages, with the exception of cardiovascular and neurosyphilis. 1–5 This group of manifestations is sometimes also called "late benign syphilis." The characteristic lesion is the gumma, and generally speaking, the longer the interval between initial infection and lesion onset, the more destructive the manifestations will be. The incidence of BTS in untreated cases is set at 16.6% in the Gjestland revision of the Bruusgaard figures, but the incidence in the general population has been steadily falling in the past 50 years, and BTS in any form has become a rare disease. Experience at the Vanderbilt clinic, for example, showed a decline in the average number of cases per five-year period from 130 in 1940 to 17 in 1951. 5 No doubt it is significantly lower now. With classically accepted exceptions—the ovary, for example, and the small intestine—BTS can affect virtually any anatomic site. The great majority of lesions are concentrated in the skin, mucous membranes, and bone, however; and the material presented in this section will deal principally with disease in those structures. The distribution of BTS by site in the series of 601 examples collected by Kampmeier6 is shown in Table 13-1. BTS lesions can appear as early as two years and as late as 35 years after the initial infection. The great majority of cases fall in the 2-to 7-year time period.
REPRESENTAÇÕES VISUAIS DE GRUPOS INDÍGENAS NO JORNAL FOLHA DE SÃO PAULO

Este artigo estuda representacoes visuais de culturas e grupos sociais considerados subalternos feitas por instituicoes dominantes e sugere que analisar a maneira pela qual imagens fazem referencia ao mundo que vivemos permite-nos compreender a ideologia subjacente a cada representacao. A investigacao e realizada a luz da abordagem pos-colonial e pos-formalista que parte do principio que a linguagem (integrando imagem) e a construcao do conhecimento do mundo sao geradas tanto dentro de um contexto socio-historico-ideologico especifico quanto dentro de relacoes socioeconomicas especificas entre os poderosos e os subalternos. O objetivo e propor que atividades de Letramento Critico Visual (Rose, 2007) levem os alunos a desenvolver ferramentas/recursos para a expansao interpretativa e a analise critica de imagens dentro da sala de aula, de forma a proporcionar-lhes oportunidades para produzir conhecimento que reconheca as nossas sociedades como multiculturais e resgate os pontos de vista dos subjugados.
Measuring and Increasing Z-Width with Active Electrical Damping

The "Z-Width" of a haptic display is the dynamic range of impedances that can be passively rendered. Haptic displays with larger Z-width generally render more realistic feeling virtual environments. We present a new method for measuring and displaying the Z- width of a haptic display. Instead of stiffness-damping plots, we believe a more illustrative technique for plotting the Z-width of a haptic interface is the envelope of achievable passive impedances as a function of frequency. Both hardware and analysis software for this new type of Z-width measurement are discussed. As previous research has shown, the maximum passive impedance that a device can render is directly related to the physical damping available in the mechanism. In an effort to maximize the Z-width of the haptic display, we present a new technique for adding physical damping to a haptic display through the use of analog electronics in the motor amplifier. Due to its electrical nature, active electrical damping has the benefit of dynamically variable parameters with no added mechanical complexity or mass. With the addition of active electrical damping, we show a performance improvement via a larger Z-width and larger range of passive virtual environment parameters.
Arbitrating a dispute: a decision analytic approach

Many collective decision-making and bargaining situations can be described through the set of the feasible joint evaluations of all conceivable settlements. Attention should then be restricted to that subset Pareto-optimal frontier from which no joint gains are possible. Hence, the focal issue becomes which element of the Pareto-optimal subset should be chosen as a solution to the dispute. This paper proposes an arbitration procedure to address this issue. The proposed approach, decision-analytic in its nature, is inspired by LaValle's LaValle, I. H. 1978. Fundamentals of Decision Analysis. Holt, Rinehart and Winston, New York. allocation-function approach which is not specific on how to obtain an allocation function and by Eliashberg and Winkler's Eliashberg, J., R. L. Winkler. 1981. Risk sharing and group decision making. Management Sci.27 November 1221-1235. work which does not accommodate probability differences within the group. After the new approach is presented, its implications are examined for some likely scenarios and examples are considered.
Tiotropium in asthma: A systematic review

Introduction The objective of this paper is to systematically review the existing evidence of the effectiveness and safety profile of a long-acting inhaled muscarinic antagonist as add-on therapy in patients with asthma that is uncontrolled despite inhaled corticosteroid (ICS) use. Methods With the assistance of two experienced research librarians, we searched Ovid MEDLINE/PubMed (1946 to September 12, 2013), the Cochrane Library review, and the TRIP database. The key search terms were "tiotropium and asthma." The search was limited to human data published in English. Included in the systematic review were all randomized controlled trials that evaluated the efficacy of tiotropium in patients with asthma. The clinical trials had to be at least 4 weeks in duration and to provide adequate information on clinically appropriate end points in asthma care (eg, change in lung function, exacerbation rates, and/or ICS dosing). Data on patient characteristics, study design, outcome measures, concomitant asthma medication, and adverse events were extracted from the full text of each included individual study. Marked heterogeneity of study design precluded statistical pooling of results for a meta-analysis. Consequently, only descriptive summaries of outcomes are provided. Results Our database search retrieved 149 citations. We found five randomized controlled trials in humans that met our criteria for inclusion in the systematic review. We also found two open-label uncontrolled trials that were considered in the discussion. Each of the five included studies met the Consolidated Standards of Reporting Trials criteria for a well-designed randomized trial. Discussion The five clinical studies included in this systematic review focused on evaluating the efficacy of tiotropium as add-on therapy to ICS or ICS in combination with a long-acting inhaled β2-agonist (LABA) in patients with uncontrolled moderate to severe persistent asthma. Tiotropium maintained lung function when ICSs were tapered and when an LABA was discontinued. Tiotropium improved lung function when added to ICS alone or ICS-LABA combination therapy. In the only trial to have compared the addition of tiotropium with doubling the dose of ICS, tiotropium provided significantly superior results. In trials in which the addition of tiotropium was compared with salmeterol, the beneficial effects of these two bronchodilators were similar. No safety concerns were found with use of tiotropium as add-on therapy. Conclusion Tiotropium may have a beneficial role in moderate to severe persistent asthma despite use of an ICS or ICS and LABA. Use of tiotropium as add-on therapy poses no safety concerns.
Mesoamerican: A Proposed Language Phylum

This report describes the preliminary findings of our research into the relationships of several groups of languages spoken in a large and relatively continuous zone of Mesoamerica. These include (1) the Mayan family of Guatemala, Belize, eastern Honduras, southern Mexico, and the Yucatan Peninsula (including Huastec spoken in northern Veracruz and eastern San Luis Potosi, Mexico); (2) the Zoquean family of southern Mexico (primarily the Mexican states of Chiapas, Oaxaca, and Veracruz); (3) the language isolate, Huave, spoken on the Pacific coast of the Isthmus of Tehuantepec in southern Mexico; (4) the Totonacan family of northcentral Veracruz and parts of the Mexican states of Hidalgo and Puebla; (5) the Lencan family of south-central Honduras and eastern El Salvador; (6) the Jicaque family of northwestern Honduras; and (7) the Otomanguean stock, which is widely distributed through southern, central, and east-central Mexico. Our research
Evidence for a simple scaling law relating neutral and cation diatomic bond energies

Abstract In the past, much chemical research has been motivated and directed by the discovery of empirical scaling laws. Today, such laws still have import, most notably as guideposts for developing better and more efficient methods of approximation in theoretical chemistry. In the course of a project examining neutral and singly-ionized cation bond energies, we have found evidence for a simple scaling law relating diatomic cation and neutral bond strengths: the loss of a valence electron from a ‘generic’ diatomic has little effect on the bond energy (i.e. D e (AB + )≅1.1 D e (AB)). Further, we find that this result varies only marginally over the population of all covalent bonds, including both singly and multiply bonded diatomics. Here, we present the evidence for this scaling law, and explore its qualitative implications for molecular structure.
Some tests of international equity integration

Abstract This paper provides tests of international equity market integration. The tests use a simple version of the consumption-based asset pricing model which predicts there is an asset pricing line for each country that relates a representative individual's expected real return on each asset to the covariance of this return with growth in the individual's real consumption. Using monthly data from January 1960 to December 1985, tests provide little evidence against the joint hypothesis that equity markets are integrated internationally and that the asset pricing model holds.
Use of Diffusion for Enzymatic Determination of Urea-Nitrogen in Soil Extracts

Abstract Urea-N in soil extracts is normally determined by colorimetric procedures using diacetyl monoxime, due in part to the use of a urease (urea amidohydrolase, EC 3.5.1.5) inhibitor to prevent urea hydrolysis during extraction. Alternatively, this determination can be done enzymatically if no inhibitor was employed in the preparation of extracts, in which case N-isotope analyses can be performed on urea as well as extractable NH4, NO3, and NO2. An accelerated diffusion method for determining exchangeable NH4 was employed to recover (urea + NH4)-N by heating 10–100 mL of soil extract at 45–50°C for 1.75–8.5 h with jack bean (Canavalia ensiformis) urease and MgO (50 mg of each). Studies using labeled urea showed ≥98% recovery of 15N as urea, with virtually no recovery as NH4, even when filtration was delayed up to 1 h after shaking 2 M KCl soil suspensions. The procedure described provides a convenient alternative to colorimetry for research concerning transformations of urea-N in soils.
Vegetative anatomy and systematics of subtribe Dendrobiinae (Orchidaceae)

Anatomy of leaf, stem, and root of more than 100 species in subtribe Dendrobiinae (Orchidaceae) was studied with the light microscope to provide a comparative anatomical treatment of these organs, to serve as an independent source of evidence that might be taxonomically important, and to recommend such reinterpretations of existing classifications as are suggested by a phylogenetic assessment of data. We based our classification on that of Rudolf Schlechter as the most complete and widely accepted today. We found that the anatomy of plants in subtribe Dendrobiinae reflects a high degree of morphological diversity, and many of the anatomical characters appear to be homoplasous. When these anatomical data are used to interpret the systematic relationships among the genera, they indicate thatDendrobiumis not monophyletic and thatCadetiaandPseuderiaare apparently nested within the structure ofDendrobiumwhen sectionGrastidiumis chosen as a functional outgroup. Lack of resolution in the strict consensus tree illustrates the difficulty of determining the phylogenetic relationships of many of Schlechter's sections using anatomical characters. Nevertheless, we recommend that his sectional classification, with appropriate modifications based on available data, be retained for the present, pending a more detailed understanding of the phylogeny of Dendrobiinae based on morphology, micromorphology, anatomy, and DNA studies.