cssi/SciSciGPT-SciSciNet huggingface dataset:
BACKGROUND TARBALL STRANDINGS ON SANDY OREGON BEACHES

ABSTRACT The New Carissa grounded February 4, 1999 near Coos Bay, Oregon and released an estimated 595 to 1,786 barrels (25,000 to 75,000 gallons) of IFO 280 and MDO. Stranded oil and tarballs were monitored on 56 segments over 280 km (150 nmiles) of central Oregon coast sand beaches for a period of over 18 months. Tarball samples were collected and analyzed by GC-MS Modified EPA 8270. Samples were qualitatively compared to oils known to be aboard the ship. To date, a total of 824 tarballs have been collected, of which 183 have been analyzed. Criteria used for selection of tarballs to be analyzed were: (1) representative of tarballs on the beach, (2) appeared to be anomalous to the New Carissa incident in terms of timing or distribution, and (3) anomalous in appearance. Samples were randomly selected within each category for analysis. Of the 141 random samples collected and analyzed, 69 (49%) were inconsistent with New Carissa source oils (NCSOs). Of 34 samples analyzed as anomalous in time and/or space, ...
Synthesis of soluble graphite and graphene.

Because of graphene’s anticipated applications in electronics and its thermal, mechanical, and optical properties, many scientists and engineers are interested in this material. Graphene is an isolated layer of the π-stacked hexagonal allotrope of carbon known as graphite. The interlayer cohesive energy of graphite, or exfoliation energy, that results from van der Waals attractions over the interlayer spacing distance of 3.34 A (61 meV/C atom) is many times weaker than the intralayer covalent bonding. Since graphene itself does not occur naturally, scientists and engineers are still learning how to isolate and manipulate individual layers of graphene. Some researchers have relied on the physical separation of the sheets, a process that can sometimes be as simple as peeling of sheets from crystalline graphite using Scotch tape. Other researchers have taken an ensemble approach, where they exploit the chemical conversion of graphite to the individual layers. The typical intermediary state is graphite oxide,...
Chronic Recurrent Goodpasture's Syndrome

A distinctive case of Goodpasture's syndrome characterized by multiple recurrences occurring over 14 years was observed. Each recurrence followed cessation of prednisone and azathioprine therapy, and reinstitution of this therapy resulted in prompt remission. Initially, both glomerulonephritis and hemoptysis were prominent clinical features. In recent years, hemoptysis has been the predominant clinical problem. This and other cases suggest that Goodpasture's syndrome may comprise a wider disease spectrum than generally appreciated.
Paramagnetic spin label interactions with the envelope of a group A arbovirus. Lipid organization.

Abstract Electron paramagnetic resonance observations were made on nitroxide spin-labeled molecules which were bound to the TC-83 vaccine strain of Venezuelan equine encephalomyelitis virus. Paramagnetic resonance parameters derived from the observations and their dependence on sample temperature were similar but not identical to those which have been reported for these labels dissolved in lipid bilayer membranes of mammalian and bacterial origin. The data are consistent with the existence of a bilayer lipid structure in the virion envelope which has a mechanical rigidity substantially greater than that of bilayers in cellular membranes. A model is presented which assumes the location of the lipid bilayer outside the nucleoprotein capsid and inside a spherical layer of envelope proteins. The model is in accord with Harrison's X-ray diffraction results for Sindbis virus. The model is discussed in terms of its implications with respect to the role played by lipid in viral maturation and infectivity.
An 1130-based logic, layout and evaluation system

A relatively small computing system can assist the engineer in performing logic design, simulation, component placement and interconnectionGraphic computer-aided design methods improve the man-machine relationship. The combination of a small computer, disk storage units, high performance display, low -cost on-line plotter and unit record I/O devices offers significant benefits to the user.Even the small-sized system is enhanced by a multitasking operating system. The major benefit realized is accessibility for the user. Any nonbusy facility can be immediately accessed by the designer; he doesn't need to wait for the current computer job to complete. The multitasking program attempts to keep all devices operating full- time, thereby offering better system utilization.Remote Job Entry (RJE) to a larger computer system via the telephone network allows the small system to handle extremely large computations for the user. The graphic system operates as a satellite to the larger system, providing the user with a powerful input/output facility, as well as performing local computation.
Chalkbrood Transmission in the Alfalfa Leafcutting Bee: The Impact of Disinfecting Bee Cocoons in Loose Cell Management Systems

Understanding pathogen transmission could illuminate new methods for disease prevention. A case in point is chalkbrood in the alfalfa leafcutting bee [Megachile rotundata (F.)]. Propagation of this solitary bee is severely hampered by chalkbrood, a larval disease caused by Ascosphaera aggregata (Ascomycota). Alfalfa leafcutting bees nest in existing cavities in wood or hollow reeds and overwinter as larvae. In the early summer, emerging adults frequently must chew through dead, diseased siblings that block their exit, becoming contaminated with chalkbrood spores in the process. When alfalfa leafcutting bees are used as a commercial pollinator, the cocoons are removed from nesting boards to reduce chalkbrood transmission, but the disease is still common. To determine if these removed cocoons (called loose cells) are an important source of disease transmission, they were disinfected with a fungicide before bees were incubated, and released in the field. Chalkbrood prevalence among the progeny of the treated bees was reduced up to 50% in one field trial, but not significantly when tested in an on-farm trial. Thus, substantial disease transmission still occurred when the loose cells were disinfected, and even when clean nesting materials were used. In conclusion, pathogen transmission must still be occurring from another source that has yet to be identified. Another possible source of transmission could arise from bees that emerge midsummer in populations with a high percent of multivoltinism, but dirty nesting boards and feral bees also may be minor sources of transmission.
Cross-stream forces and velocities of fixed and freely suspended particles in viscoelastic Poiseuille flow: Perturbation and numerical analyses

The cross-stream migration of a circular particles (or infinitely long cylinder) in two dimensional, inertialess viscoelastic pressure-driven flows is examined through complementary finite element simulations and second-order fluid perturbation analyses for small Deborah number (De), where De is defined as the fluid relaxation time divided by the characteristic flow time. A neutrally buoyant, freely suspended particle migrates toward the center of the channel for all particle sizes and cross-stream positions due to the coupled effects of the linear and quadratic variations of the imposed velocity. A particle that is held at a fixed position, in contrast, experiences a cross-stream force directed toward the wall as a result of the coupled effects of the local shear flow and the flow relative to the particle. © 2010 Elsevier B.V. All rights reserved.
Making Location Decision Based on Regional Industrial Capabilities: A Case of a Distributor

This article presents a structured process to make facility location decisions based on regional industrial capabilities. It presents a framework for collecting business intelligence on major cities of the region of interest. In the next step, the collected business intelligence is incorporated into a quantitative decision analysis model for facility location. While the proposed framework is generic and builds on the existing international business and supply chain management literature, the article mainly focuses on the facility location problem of a distribution firm that is not well represented in the literature. Two cases—one each for new and established distributors who are trying to sell to the Mexican market—are presented in the article.
Using a system mixed-effects modeling method to estimate tree compartment biomass for intensively managed loblolly pines—an allometric approach

Allometric relationships between total and individual tree compartment (stem, root, branch, and foliage) biomass were investigated for intensively managed loblolly pine (Pinus taeda L.) plantations in the Lower Coastal Plain and Piedmont of Georgia. It was found that the percent of stem biomass increases with age while the inverse relationship was found for foliage and branches. Cultural treatments also impacted the proportional allocation among various tree compartments. Specifically, this investigation showed that compared with unfertilized trees, annually fertilized trees in the Lower Coastal Plain had a larger proportional biomass allocation to the stem relative to root, branch, and foliage compartments. A system of related compartment biomass models was developed that reproduces observed relationships in the raw data. This system of models uses total tree biomass to obtain estimates of biomass for other tree compartments. The flexibility of the system of biomass prediction models allows users to estimate biomass for the various compartments as a function of another known compartment biomass.
Communicative adaptability: A measure of social communicative competence

The purpose of this research was to reassess the validity and increase the variance accounted for by the Communicative Adaptability Scale (CAS). Previous research produced two factors, social confirmation and social experience, accounting for 28% of the variance. The present study tested the inclusion of four additional dimensions: social composure, articulation, wit, and appropriate disclosure. The Communicative Adaptability Scale was administered to adult and student populations. The relationships among the dimensions of the CAS, self‐esteem, and communication apprehension were investigated. This project indicated a stable factor structure and consistent results across samples.
CloudStash: Using Secret-Sharing Scheme to Secure Data, Not Keys, in Multi-clouds

Cloud storages have many exciting features that attract many individuals and organizations for storing and sharing data over the cloud. However, security and key management are still remaining the highlighted concerns in cloud storage. Managing/protecting keys is a problem for existing approaches, and opens the risk of attackers working to offline brute-force crack the decryption and/or surreptitiously obtaining the key and using it offline. To address these issues, we propose the Cloud Stash scheme, a system that applied the secret-sharing scheme directly on the file to store multi-shares of a file into multi-clouds. Cloud Stash utilizes secret-sharing, low cost cloud storages and multi-threading to improve confidentiality, availability, performance and fault tolerance. Cloud Stash achieves this improvement by splitting a file into multi-shares of secret and distributing these multi-shares into multi-clouds simultaneously where threshold shares are required to reconstruct the file. Our experiments show that Cloud Stash is statistically significantly faster for small files, and even for large files the added cost is not statistically worse. So the added security benefits are nearly free from the users' perspective.
Solar Probe Plus: A mission to touch the sun

Solar Probe Plus (SPP), currently in Phase B, will be the first mission to fly into the low solar corona, revealing how the corona is heated and the solar wind is accelerated, solving two fundamental mysteries that have been top priority science goals since such a mission was first proposed in 1958. The scale and concept of such a mission has been revised at intervals since that time, yet the core has always been a close encounter with the Sun. SPP uses an innovative mission design, significant technology development and a risk-reducing engineering development to meet the SPP science objectives: 1) determine the structure and dynamics of the magnetic fields at the sources of the fast and slow solar wind, 2) trace the flow of energy that heats the corona and accelerates the solar wind. and 3) determine what mechanisms accelerate and transport energetic particles. In this paper, we present the Solar Probe Plus mission along with a brief comparison with some previous concepts for such a mission, and discuss the trade studies that led to the SPP implementation. We present a summary of the challenges associated with operation in the solar encounter environment and discuss the technology development and engineering trade studies to compose a mission that will not only survive this environment, but will provide the data needed to answer the science questions that have remained unanswered to date.
Japanese Medaka (Oryzias latipes): Developmental Model for the Study of Alcohol Teratology

BACKGROUND: Animal models are necessary to investigate the mechanism of alcohol-induced birth defects. We have used Japanese medaka (Oryzias latipes) as a non-mammalian model to elucidate the molecular mechanism(s) of ethanol teratogenesis. METHODS: Medaka eggs, within 1 hr post-fertilization (hpf) were exposed to waterborne ethanol (0–1000 mM) in hatching solution for 48 hr. Embryo development was observed daily until 10 days post-fertilization (dpf). The concentration of embryonic ethanol was determined enzymatically. Cartilage and bones were stained by Alcian blue and calcein, respectively and skeletal and cardiovascular defects were assessed microscopically. Genetic gender of the embryos was determined by PCR. Levels of two isoenzymes of alcohol dehydrogenase (Adh) mRNAs were determined by semi-quantitative and real-time RT-PCR. RESULTS: The concentration of ethanol required to cause 50% mortality (LC50) in 10 dpf embryos was 568 mM, however, the embryo absorbed only 15–20% of the waterborne ethanol at all ethanol concentrations. The length of the lower jaw and calcification in tail fin cartilaginous structures were reduced by ethanol exposure. Active blood circulation was exhibited at 50+ hpf in embryos treated with 0–100 mM ethanol; active circulation was delayed and blood clots developed in embryos treated with 200–400 mM ethanol. The deleterious effects of ethanol were not gender-specific. Moreover, ethanol treatment was unable to alter the constitutive expression of either Adh5 or Adh8 mRNA in the medaka embryo. CONCLUSIONS: Preliminary results suggested that embryogenesis in medaka was significantly affected by ethanol exposure. Phenotypic features normally associated with ethanol exposure were similar to that observed in mammalian models of fetal alcohol syndrome. The results further indicated that medaka embryogenesis might be used as an alternative non-mammalian model for investigating specific alterations in gene expression as a means to understand the molecular mechanism(s) of ethanol-induced birth defects. Birth Defects Res (Part B) 77:29–39, 2006. © 2006 Wiley-Liss, Inc.
Unexpected Reduction of Skin Tumorigenesis on Expression of Cyclin-Dependent Kinase 6 in Mouse Epidermis

Cyclin-dependent kinases (CDKs) 4 and 6 are important regulators of the G1 phase of the cell cycle, share 71% amino acid identity, and are expressed ubiquitously. As a result, it was assumed that each of these kinases plays a redundant role regulating normal and neoplastic proliferation. In previous reports, we have described the effects of CDK4 expression in transgenic mice, including the development of epidermal hyperplasia and increased malignant progression to squamous cell carcinoma. To study the role of CDK6 in epithelial growth and tumorigenesis, we generated transgenic mice carrying the CDK6 gene under the keratin 5 promoter (K5CDK6). Similar to K5CDK4 mice, epidermal proliferation increased substantially in K5CDK6 mice; however, no hyperplasia was observed. CDK6 overexpression also triggered keratinocyte apoptosis in interfollicular and follicular epidermis as a compensatory mechanism to override aberrant proliferation. Unexpectedly, CDK6 overexpression results in decreased skin tumor development compared with wild-type siblings. The inhibition in skin tumorigenesis was similar to that previously reported in K5-cyclin D3 mice. Furthermore, biochemical analysis of the K5CDK6 epidermis showed preferential complex formation between CDK6 and cyclin D3, suggesting that this particular complex plays an important role in tumor restraint. These studies provide in vivo evidence that CDK4 and CDK6 play a similar role as a mediator of keratinocyte proliferation but differ in apoptosis activation and skin tumor development.
Assessment of phantom dosimetry and image quality of i-CAT FLX cone-beam computed tomography

Introduction The increasing use of cone-beam computed tomography in orthodontics has been coupled with heightened concern about the long-term risks of x-ray exposure in orthodontic populations. An industry response to this has been to offer low-exposure alternative scanning options in newer cone-beam computed tomography models. Methods Effective doses resulting from various combinations of field of view size and field location comparing child and adult anthropomorphic phantoms with the recently introduced i-CAT FLX cone-beam computed tomography unit (Imaging Sciences, Hatfield, Pa) were measured with optical stimulated dosimetry using previously validated protocols. Scan protocols included high resolution (360° rotation, 600 image frames, 120 kV[p], 5 mA, 7.4 seconds), standard (360°, 300 frames, 120 kV[p], 5 mA, 3.7 seconds), QuickScan (180°, 160 frames, 120 kV[p], 5 mA, 2 seconds), and QuickScan+ (180°, 160 frames, 90 kV[p], 3 mA, 2 seconds). Contrast-to-noise ratio was calculated as a quantitative measure of image quality for the various exposure options using the QUART DVT phantom. Results Child phantom doses were on average 36% greater than adult phantom doses. QuickScan+ protocols resulted in significantly lower doses than standard protocols for the child (P = 0.0167) and adult (P = 0.0055) phantoms. The 13 × 16-cm cephalometric fields of view ranged from 11 to 85 μSv in the adult phantom and 18 to 120 μSv in the child phantom for the QuickScan+ and standard protocols, respectively. The contrast-to-noise ratio was reduced by approximately two thirds when comparing QuickScan+ with standard exposure parameters. Conclusions QuickScan+ effective doses are comparable with conventional panoramic examinations. Significant dose reductions are accompanied by significant reductions in image quality. However, this trade-off might be acceptable for certain diagnostic tasks such as interim assessment of treatment results.
Evaluation of Atmospheric Aerosol Particle Size Distribution from Scattering Measurements in the Visible and Infrared

The atmospheric aerosol particle size distribution was examined using measured spectral scattering coefficients in the wavelength region 0.40–2.27 μ. It was found that the aerosol on a particular day can be represented by a two-component composite, the main component having a Junge distribution of the form dN/d logr = Cr−n and the other having either a distribution of larger particles similar to that of aerosols found in maritime air or a relatively monodisperse distribution contained in a narrow radius interval. This study shows that estimates of aerosol size distribution may be in error if based only on attenuation measurements in the visible region.
Organofunctionalized montmorillonite/epoxy nanocomposites: The effect of interlayer cation distribution on mechanical properties

The present study indicates that a distribution of alkylammonium chain lengths in the interlayer of montmorillonite (MM) results in a greater degree of dispersion into an epoxy matrix (or possibly different polymer matrices) and improved ultimate tensile strengths. This hypothesis is supported by x-ray diffraction (XRD) data from the modified MM clays, which clearly shows that an increase in d-spacing does not result in an improvement in tensile strengths. Additional support is obtained from DSC analyses of the first and second heats of the treated clays which indicate that the C6 alkyl amine in a deposited (C18 + C6) alkyl ammonium mixture results in intercalation pathways for the epoxy resin. POLYM. COMPOS., 32:67-78, 2011. © 2010 Society of Plastics Engineers.
647 – The driver behaviour, violations, errors, lapses on roads: a cross cultural comparison of four countries

Aim To investigate the cross cultural difference in driver behaviours; violations, errors and lapses and compare driving behaviours of four countries; Qatar, Jordan, Indian subcontinent and Philippines. Subjects and methods The Manchester Driver Behaviour Questionnaire (DBQ) was used to measure the driving behaviour and accident involvement. A representative sample of 1,824 drivers participated. Results Majority of the Qatari (35.9%) and Jordanian drivers (37.5%) were below 30 years, whereas Philippino (42.3%) and Indian subcontinental (34.1%) drivers were in the age group 30-39 years. Qatari drivers (52%) were more involved in accidents, followed by Jordanians (48.3%). The most common type of collision was head on collision which was similar in four countries. The Qatari drivers scored higher on almost all items of violations, errors and lapses, while Philipino drivers were lower on all the items. All ten items of violations were reported in the Qatar sample. “Disregard the speed limits on a motorway” was the violation observed more frequent in four countries. Errors were reported less in all countries. “Queing to turn right/left on to a main road…… nearly hit the car” was the most common error observed in studied drivers. Lapses were higher in Indian drivers, followed by Qatari and Jordanian drivers. “Forget where you left your car …….hit something when reversing” were the two most common lapses reported in four countries. Conclusion Qatari drivers scored higher on most of the items of violations, errors and lapses compared to other countries, whereas Philippino drivers scored lower in DBQ items.
A Rigorous Solution to the Low-Frequency Breakdown in Full-Wave Finite-Element-Based Analysis of General Problems Involving Inhomogeneous Lossless/Lossy Dielectrics and Nonideal Conductors

Existing methods for solving the low-frequency breakdown problem associated with full-wave solvers rely on low-frequency approximations, which has left a number of research questions to be answered. The conductors are also generally treated as perfect conductors and the dielectric loss is not considered. In this work, a rigorous method that does not utilize low-frequency approximations is developed to eliminate the low frequency breakdown problem for the full-wave finite-element based analysis of general 3-D problems involving inhomogeneous lossless and/or lossy dielectrics and nonideal conductors. This method has been validated by the analysis of realistic on-chip circuits at frequencies as low as dc. Furthermore, it is applicable to both low and high frequencies. In this method, the frequency dependence of the solution to Maxwell's equations is explicitly and rigorously derived from dc to high frequencies. In addition to eliminating the low-frequency breakdown, such a theoretical model of the frequency dependence can be used to understand how the field solution, in a complicated 3-D problem with both lossless/lossy inhomogeneous dielectrics and nonideal conductors, should scale with frequency and at which frequency full-wave effects become important.
Carbon monoxide oxidation on nickel oxide

Abstract The oxidation of carbon monoxide over nickel oxide has been studied at 160–180 °C for partial pressures of CO in the order of 33 Torr. Gases tagged with 13C and 18O have been used to obtain insight concerning the sequence of steps in the reaction. Apparently CO is oxidized in two ways: The reaction of CO(g) with adsorbed oxygen leading to CO2(g); and the reaction of CO(g) with adsorbed CO2 to form a two-carbon intermediate, which then is further oxidized to 2CO2(g).
Water-exclusion and liquid-structure forces in implicit solvation.

A continuum model of solvation is proposed to describe (i) long-range electrostatic effects of water exclusion resulting from incomplete and anisotropic hydration in crowded environments and (ii) short-range effects of liquid-structure forces on the hydrogen-bond interactions at solute/water interfaces. The model is an extension of the phenomenological screened coulomb potential-based implicit model of solvation. The developments reported here allow a more realistic representation of highly crowded and spatially heterogeneous environments, such as those in the interior of a living cell. Only the solvent is treated as a continuum medium. It is shown that the electrostatic effects of long-range water-exclusion can strongly affect protein–protein binding energies and are then related to the thermodynamics of complex formation. Hydrogen-bond interactions modulated by the liquid structure at interfaces are calibrated based on systematic calculations of potentials of mean force in explicit water. The electrosta...
The study of environmental public policy: A preliminary directory

Selected contributions to the study of environmental public policy are reviewed in the context of the difficulties faced in making such studies cumulative. The information obtained for a preliminary directory of students of environmental public policy is outlined and briefly analyzed. The directory itself is presented.
Cushion plants as islands.

The acarine fauna of two abundant species of cushion plant on the high, short-grass prairie of S.E. Wyoming were used to test The MacArthur-Wilson Theory of Island Biogeography. Multiple regression analysis using area, distance and percent moisture as independent variables and number of mite species and number of mite individuals were run for the two sampling dates. Results showed area alone to be consistently and highly correlated (r=0.84–0.94) with both species and individuals for one cushion species. The slopes of the species-area and individuals-area curves are among the highest recorded and were significantly higher on the second sampling date. Selective seasonal changes in the fauna were shown by increases both in numbers of species and individuals, mainly on larger cushions, for the later sampling period. It is hypothesized that seasonal changes are due to an increase in the number of predator species in response to an increase in the number of prey items. The slopes of the species-area curves are compared with those in the literature and it is argued that slope values are more dependent upon the taxonomic group being studied than on whether the island is insular or oceanic. Finally, we suggest that The MacArthur-Wilson Theory is not applicable to islands which 1) exhibit continuous growth, 2) lack a discrete species source, and 3) are relatively transitory.
Band structure calculation of photonic crystal slab by using plane wave expansion method with perfectly matched layers

In this paper, we presented a new algorithm for the band structure calculation of photonic crystal slabs (PCS) based on the plane wave expansion method (PWEM) with perfectly matched layers (PMLs). The introduction of PMLs is used to truncate the computational region in the vertical direction. In addition, the effective medium tensor is applied to improve the convergence. By using PWM, a general complex eigenvalue problem is then obtained. Two criterions are presented to distinguish the guided modes from the PML modes. The presented scheme can accurately determine the band structure both above and below the light cone. The results obtained using this algorithm have been compared with those by using Finite-difference Time-Domain (FDTD) method and found to agree very well.
Normal vibrations of two parallel-coupled diatomic linear lattices: Method of intermediate coordinate transformation

Abstract A new method of vibrational analysis (intermediate coordinate transformation) is described from a purely mechanical point of view by applying it to a system of two parallel-coupled diatomic linear lattices. The method is a modification of the method of extra forces that was presented earlier in this journal [1]. In this method, the system is regarded as a superposition of four monatomic linear chains, M-particle and m-particle chains for each lattice, coupled together to form a planar lattice model. The complete energy expressions for the system are first transformed into those in terms of the normal coordinates of the separate monatomic chains. The normal-mode solution for the system obtained from such energy expressions is the result of coupling various modes of the separate chains. Because the coupling of the modes is restricted by the symmetry properties of the normal modes, the intermediate coordinate transformation simplifies the problem. The method described here can be applied to more complicated lattice models to facilitate the analysis.
Chemical Decomposition of 5-Aza-2'-deoxycytidine (Decitabine): Kinetic Analyses and Identification of Products by NMR, HPLC, and Mass Spectrometry

The nucleoside analogue 5-aza-2′-deoxycytidine (Decitabine, DAC) is one of several drugs in clinical use that inhibit DNA methyltransferases, leading to a decrease of 5-methylcytosine in newly replicated DNA and subsequent transcriptional activation of genes silenced by cytosine methylation. In addition to methyltransferase inhibition, DAC has demonstrated toxicity and potential mutagenicity, and can induce a DNA-repair response. The mechanisms accounting for these events are not well understood. DAC is chemically unstable in aqueous solutions, but there is little consensus between previous reports as to its half-life and corresponding products of decomposition at physiological temperature and pH, potentially confounding studies on its mechanism of action and long-term use in humans. Here, we have employed a battery of analytical methods to estimate kinetic rates and to characterize DAC decomposition products under conditions of physiological temperature and pH. Our results indicate that DAC decomposes in...
Dendrimers as Building Blocks for Nanostructured Materials: Micro- and Mesoporosity in Dendrimer-Based Xerogels

Second and third generation silylalkoxy-terminated carbosilane dendrimers have been used to make high surface area xerogels via an acid-catalyzed sol-gel protocol. These xerogels are micro- and mesoporous and contain a high degree of −OH functionality. An unexpected trend with respect to dendrimer generation and xerogel surface area is described. These xerogels may have applications as (for example) catalyst supports and porous membranes.
Endogenous adenosine, A1 adenosine receptor, and pertussis toxin sensitive guanine nucleotide binding protein mediate hypoxia induced AV nodal conduction block in guinea pig heart in vivo

Objective: The aim was to study the mechanism of global hypoxia induced atrioventricular (AV) nodal conduction block in vivo using a guinea pig model. Methods: Animals subjected to 10 min periods of global hypoxia, induced by decremental changes in O2 content in the inhaled gas mixture, were randomly divided into three groups: group I=control; group II=animals treated with a new selective A1 adenosine receptor antagonist, N0861 (N6-endo-norbornan-2-yl-9-methyladenine); and group III - animals treated with pertussis toxin, an irreversible inhibitor of specific guanine nucleotide binding proteins (G protein). Results: Progressive incremental hypoxia was associated with progressive AV nodal conduction delay culminating in a complete block. In addition, there was an inverse relationship between the severity of hypoxia and time to AV nodal block. Both N0861 and pertussis toxin treatment significantly reduced the degree of hypoxia induced AV nodal conduction block and delayed its appearance. Conclusions: (1) Endogenous adenosine released during acute global hypoxia causes AV nodal conduction block observed under these conditions in the guinea pig heart in vivo; and (2) this action of adenosine in the AV node is mediated by an A1 adenosine receptor and a pertussis toxin sensitive G protein. Cardiovascular Research 1993; 27 :134-140
Genetic loci that regulate healing and regeneration in LG/J and SM/J mice.

MRL mice display unusual healing properties. When MRL ear pinnae are hole punched, the holes close completely without scarring, with regrowth of cartilage and reappearance of both hair follicles and sebaceous glands. Studies using (MRL/lpr × C57BL/6)F2 and backcross mice first showed that this phenomenon was genetically determined and that multiple loci contributed to this quantitative trait. The lpr mutation itself, however, was not one of them. In the present study we examined the genetic basis of healing in the Large (LG/J) mouse strain, a parent of the MRL mouse and a strain that shows the same healing phenotype. LG/J mice were crossed with Small (SM/J) mice and the F2 population was scored for healing and their genotypes determined at more than 200 polymorphic markers. As we previously observed for MRL and (MRL × B6)F2 mice, the wound-healing phenotype was sexually dimorphic, with female mice healing more quickly and more completely than male mice. We found quantitative trait loci (QTLs) on chromosomes (Chrs) 9, 10, 11, and 15. The heal QTLs on Chrs 11 and 15 were linked to differential healing primarily in male animals, whereas QTLs on Chrs 9 and 10 were not sexually dimorphic. A comparison of loci identified in previous crosses with those in the present report using LG/J × SM/J showed that loci on Chrs 9, 11, and 15 colocalized with those seen in previous MRL crosses, whereas the locus on Chr 10 was not seen before and is contributed by SM/J.
Update on Percutaneous Management of Chronic Total Occlusion

Management of chronic total occlusions (CTOs) remains a challenge for interventional cardiologists. Despite advances in the design of angioplasty hardware and increased operator experience, percutaneous angioplasty of CTO still is associated with a relatively low primary success rate compared with non-CTO. Although the stent has dramatically improved initial and long-term outcome, the incidence of restenosis and reocclusion continues to be high in patients with excessive lesion length and/or small vessel size. Adjunctive pharmacotherapy, such as platelet glycoprotein IIb/IIIa receptor antagonist, may play an important role in the prevention of early reocclusion as well as late restenosis. Similarly, radiation therapy may be useful in the prevention/treatment of in-stent restenosis. Although observational data have shown a poor long-term survival in patients with CTO, convincing prospective or randomized data are lacking. Future investigations will need to focus on the long-term outcome of patients with CTO referred for angioplasty compared with CABG or medical therapy.
Cusum quality control-multivariate approach

A new multivariate approach to quality control is presented. On the basis of sequential probability ratio tests, a multivariate cumulative sum chart is derived. Using an approximation to the noncentral x2 distribution, a linear decision rule is obtained.
Hysteretic electroluminescence in organic light-emitting diodes for spin injection

Organic light-emitting diodes with ferromagnetic contacts are fabricated, and their emission intensity is studied at room temperature for parallel and antiparallel magnetization configuration of anode and cathode. Sweeping the magnetic field applied parallel to the electrode allows the magnetization of the two electrodes to be switched independently. The electroluminescence intensity for the antiparallel magnetic configuration is found to be enhanced as compared to the parallel one. We show that this increase is not evidence of spin injection but is a consequence of the magnetic-field dependence of the electroluminescence intensity combined with magnetic stray fields from the electrodes.
Shuttle Contamination Effects On Ultraviolet Coronagraphic Observations

The ultraviolet light coronagraph being developed for Shuttle by the Harvard-Smithsonian Center for Astrophysics is described. Effects of Shuttle contaminants on ultraviolet coronagraphic observations are discussed and column densities for acceptable attenuation are provided which are generally applicable to high spectral resolution measurements in the 600 A -1700 A spectral range.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Epigallocatechin-3-gallate (EGCG) protects against chromate-induced toxicity in vitro.

Abstract Hexavalent chromium [Cr(VI)] is a human carcinogen that results in the generation of reactive oxygen species (ROS) and a variety of DNA lesions leading to cell death. Epigallocatechin-3-gallate (EGCG), the major polyphenol present in green tea, possesses potent antioxidative activity capable of protecting normal cells from various stimuli-induced oxidative stress and cell death. Here we demonstrated that co-treatment with EGCG protected human normal bronchial epithelial BEAS-2B cells from Cr(VI)-induced cell death in a dose-dependent manner. Cr(VI) induces apoptosis as the primary mode of cell death. Co-treatment of BEAS-2B cells with EGCG dose-dependently suppressed Cr(VI)-induced apoptosis. Fluorescence microscopic analyses and quantitative measurement revealed that EGCG significantly decreased intracellular levels of ROS induced by Cr(VI) exposure. Using a well-established K + /SDS precipitation assay, we further showed that EGCG was able to dose-dependently reduce DNA–protein cross-links (DPC), lesions that could be partially attributed to Cr(VI)-induced oxidative stress. Finally, analyses of Affymetrix microarray containing 28,869 well-annotated genes revealed that, among the 3412 genes changed more than 1.5-fold by Cr(VI) treatment, changes of 2404 genes (70%) were inhibited by pretreatment of EGCG. Real-time PCR confirmed the induction of 3 genes involved in cell death and apoptosis by Cr(VI), which was eliminated by EGCG. In contrast, Cr(VI) reduced the expression of 3 genes related to cellular defense, and this reduction was inhibited by EGCG. Our results indicate that EGCG protects BEAS-2B cells from Cr(VI)-induced cytotoxicity presumably by scavenging ROS and modulating a subset of genes. EGCG, therefore, might serve as a potential chemopreventive agent against Cr(VI) carcinogenesis.
Hydride habit planes in titanium-aluminum alloys

The habit plane of hydride precipitates in pure Ti has been previously reported as being predominantly the {10-10} prism plane, with precipitation also taking place on {10-11} planes, while habit planes in a Ti-3 pet Al alloy were {10-11} {11-21} and {10-12}. No habit planes near the basal plane have been reported in Ti alloys, although the {10-17} plane (14 deg from the basal plane) has been observed in certain zirconium alloys. In this work, Ti single crystals containing up to 6.6 wt pet Al were charged with hydrogen and the ef-fect of Al on hydride habit plane observed with both transmission and optical microscopy. Hydrides with a basal and near-basal habit plane were found in the higher Al content al-loys and it is suggested that the increased propensity for basal slip in these alloys is the reason for the change in habit plane. The implications of these observations in under-standing hydrogen induced fracture in Ti alloys are discussed, and possible modifica-tions to the conclusions of other investigators in this field suggested.
Methanogenic population dynamics during startup of a full-scale anaerobic sequencing batch reactor treating swine waste

Abstract Changes in methanogenic population levels were followed during startup of a full-scale, farm-based anaerobic sequencing batch reactor (ASBR) and these changes were linked to operational and performance data. The ASBR was inoculated with anaerobic digester sludge from a municipal wastewater treatment facility. During an acclimation period of approximately 3 months, the ASBR content was diluted to maintain a total ammonia-N level of approximately 2000 mg l−1. After this acclimation period, the volatile solids loading rate was increased to its design value of 1.7 g l−1 day−1 with a 15-day hydraulic retention time, which increased the total ammonia-N level in the ASBR to approximately 3600 mg l−1. The 16 S ribosomal RNA (rRNA) levels of the acetate-utilizing methanogens of the genus Methanosarcina decreased from 3.8% to 1.2% (expressed as a percentage of the total 16 S rRNA levels) during this period, while the 16 S rRNA levels of Methanosaeta concilii remained low (below 2.2%). Methane production and reactor performance were not affected as the 16 S rRNA levels of the hydrogen-utilizing methanogens of the order Methanomicrobiales increased from 2.3% to 7.0%. Hence, it is likely that during operation with high ammonia levels, the major route of methane production is through a syntrophic relationship between acetate-oxidizing bacteria and hydrogen-utilizing methanogens. Anaerobic digestion at total ammonia-N levels exceeding 3500 mg l−1 was sustainable apparently due to the acclimation of hydrogen-utilizing methanogens to high ammonia levels.
A temperature-sensitive IE1 protein of Autographa californica nuclear polyhedrosis virus has altered transactivation and DNA binding activities.

Abstract The temperature-sensitive mutant ts B821 of Autographa californica nuclear polyhedrosis virus has two nucleotide transitions in the transregulatory ie 1 gene (Riblero et al. (1994) J. Virol. 68, 1075-1084). These mutations result in two conservative amino acid substitutions in the encoded protein. To determine whether the mutations affect the ability of IE1 to interact with viral enhancer elements, electrophoretic mobility shift assays were performed using extracts prepared from infected cells and a fragment of the viral enhancer element hr5. When binding reactions. Were assembled on ice, the extracts prepared from tsB821-infected cells showed wild-type levels of DNA binding activity, whether the infected cells were grown at the permissive or nonpermissive temperature. However, when binding reactions were incubated at 33°, enhancer binding activity was significantly reduced in the ts extract. This suggests that the ts phenotype results from reduced interactions of tsIE1 with the viral enhancer elements. Site-directed mutagenesis was used to construct plasmids encoding IE1 with both of the amino acid substitutions (tsIE1) and with each of the single substitutions. tsIE1 was expressed in transient assays and exhibited thermolabile enhancer binding activity. However, proteins with single substitutions did not accumulate to detectable levels and did not exhibit enhancer binding activity. Temperature shift-up experiments with tsB821 indicated that late genes were expressed at wt levels when cells were shifted to the nonpermissive temperature during the early phase. This suggests that IE1 is not directly and continuously required for expression of late genes. However, polyhedrin expression was decreased in the mutant-infected cells when the temperature was shifted during the early or late phases of infection. Together, these results suggest that IE1 may differentially affect expression of these two classes of genes.
Financing development in less developed countries

Defining development and measuring growth is not an easy task. Countries without adequate internal capital seek financial aid from external sources. Private, direct investment from foreign sources has been inadequate for financing growth. Debt and development assistance in the form of grants has been necessary for financing less developed country growth. Foreign debt and foreign equity have contributed to growth and development unequally. This paper examines the relationship between development and financing in 15 less developed countries.
The distribution of two cell surface determinants of mouse embryonal carcinoma and early embryonic cells.

Abstract This study examines the distribution of two carbohydrate determinants recognized by monoclonal antibodies EMA-1 and EMA-6 on cells in culture, adult mouse tissues and day 0–7 embryos, and provides partial biochemical characterization of the molecules carrying the determinants for EMA-1 on embryonal carcinoma cells. Both antigens are present on primordial germ cells of day 8-day 10 mouse embryos (Hahnel and Eddy, 1986), and are expressed recurrently on pluripotent cells during earlier embryogenesis. Both antigens are also present on mouse embryonal carcinoma cells and the same set of adult tissue types. However, the distribution of the EMA-6 determinant on adult urogenital epithelia and during embryogenesis is more restricted than that of EMA-1. The determinants are detected only on lumenal surfaces of epithelial cells, suggesting that they are either not involved in processes of cell-cell or cell-substrate interaction, or are masked or altered during such interactions. Present biochemical evidence suggests that EMA-1 determinant on Nulli SCC1 cells may be on a large glycoprotein or a glycoprotein complex that is firmly attached to the cell membrane.
Acute and Chronic Effects of Opioids on δ and μ Receptor Activation of G Proteins in NG108‐15 and SK‐N‐SH Cell Membranes

To compare activation of G proteins by opioid receptors, opioid agonist-stimulated guanosine 5'-O-(3-[35S]thiotriphosphate) ([35S]GTP gamma S) binding in the presence of excess GDP was assayed in membranes from NG108-15 (delta) and SK-N-SH (primarily mu) cells. Basal [35S]GTP gamma S binding consisted of a single class of low-affinity sites (KD 400-500 nM). Addition of agonists produced a high-affinity site 100-300-fold higher in affinity than the basal site. The receptor/transducer amplification factor (ratio of activated G protein Bmax to opioid receptor Bmax) was 10-fold higher for SK-N-SH mu receptors than for NG108-15 delta receptors. Chronic delta agonist ([D-Ser2]-Leu-enkephalin-Thr; DSLET) treatment of NG108-15 cells resulted in an 80% loss of DSLET-stimulated [35S]-GTP gamma S binding within 1 h. Morphine treatment of SK-N-SH cells decreased mu agonist ([D-Ala2, N-Me-Phe4,Gly5-ol]-enkephalin; DAMGO)-stimulated [35S]GTP gamma S binding by 45% after 16 h, with no effect after 1 h. Loss of agonist response was due to a decrease in the Bmax of activated G proteins with no change in the KD. These results provide a quantitative description of G protein activation occurring on acute and chronic exposure to opioid agonists.
An empirical analysis of three econometric frameworks for evaluating economic impacts of transportation infrastructure expenditures across countries

Transportation infrastructure expenditures can lead to greater productivity and increases in economic output due to the reduction in transportation costs, improvements in access to markets and raw materials, reduction in travel times, congestion reductions, and many other benefits. These benefits can potentially allow countries to improve their comparative economic advantages. To better understand the impact of transportation infrastructure expenditures on national economies, the present paper undertakes an aggregate study of the relationship between transportation infrastructure expenditure and gross domestic product from economies in 40 countries. Three econometric frameworks (ordinary least squares, random-effects and random-parameters models) were used to investigate the impacts of transportation infrastructure expenditure across countries using data from 1992 to 2010. The random-parameters model was observed to adequately account for possible unobserved heterogeneity across countries. As expected, the estimation results showed considerable variability across countries, with the impact of transportation infrastructure expenditure varying greatly as a function of the country’s existing transportation infrastructure and the reliance of specific economic sectors on transportation in each nation.