cssi/SciSciGPT-SciSciNet huggingface dataset:
An Efficient Approach for the Reliability Analysis of Phased-Mission Systems with Dependent Failures

We consider the reliability analysis of phased-mission systems with common-cause failures in this paper. Phased-mission systems (PMS) are systems supporting missions characterized by multiple, consecutive, and nonoverlapping phases of operation. System components may be subject to different stresses as well as different reliability requirements throughout the course of the mission. As a result, component behavior and relationships may need to be modeled differently from phase to phase when performing a system-level reliability analysis. This consideration poses unique challenges to existing analysis methods. The challenges increase when common-cause failures (CCF) are incorporated in the model. CCF are multiple dependent component failures within a system that are a direct result of a shared root cause, such as sabotage, flood, earthquake, power outage, or human errors. It has been shown by many reliability studies that CCF tend to increase a system's joint failure probabilities and thus contribute significantly to the overall unreliability of systems subject to CCF.We propose a separable phase-modular approach to the reliability analysis of phased-mission systems with dependent common-cause failures as one way to meet the above challenges in an efficient and elegant manner. Our methodology is twofold: first, we separate the effects of CCF from the PMS analysis using the total probability theorem and the common-cause event space developed based on the elementary common-causes; next, we apply an efficient phase-modular approach to analyze the reliability of the PMS. The phase-modular approach employs both combinatorial binary decision diagram and Markov-chain solution methods as appropriate. We provide an example of a reliability analysis of a PMS with both static and dynamic phases as well as CCF as an illustration of our proposed approach. The example is based on information extracted from a Mars orbiter project. The reliability model for this orbiter considers the various phases of Launch, Cruise, Mars Orbit Insertion, and Orbit. Some of the CCF for the orbiter in this mission include environmental effects, such as micrometeoroids, human operator errors, and software errors.
Contributing Factors to Window Flashover under Pulsed High Power Microwave Excitation at High Altitude

One of the major limiting factors for the transmission of high power microwave (HPM) radiation is the interface between dielectric-vacuum or even more severely between dielectric-air if HPM is to be radiated into the atmosphere. Surface flashover phenomena which occur at these transitions severely limit the power levels which can be transmitted. It is of major technological importance to predict surface flashover events for a given window geometry, material and power level. When considering an aircraft based high power microwave platform, the effects on flashover formation due to variances in the operational environment corresponding to altitudes from sea level to 50,000 feet (760 to 90 Torr; 1 Torr=133.3 Pa) are of primary interest. The test setup is carefully designed to study the influence of each atmospheric variable without the influence of high field enhancement or electron injecting metallic electrodes. Experimental data of flashover delay times across different materials, such as polycarbonate, Teflonreg, and high density polyethylene as a function of background pressure and gas type, air, N2, argon are discussed. An empirical relationship between flashover field amplitude and delay time is given.
An online mechanism for ad slot reservations with cancellations

Many advertisers (bidders) use Internet systems to buy display advertisements on publishers' webpages or on traditional media such as radio, TV and newsprint. They seek a simple, online mechanism to reserve ad slots in advance. On the other hand, media publishers (sellers) represent a vast and varying inventory, and they too seek automatic, online mechanisms for pricing and allocating such reservations.We propose and study a simple model for auctioning such ad slot reservations in advance. A seller will display a set of slots at some point T in the future. Until T, bidders arrive sequentially and place a bid on the slots they are interested in. The seller must decide immediately whether or not to grant a reservation. Our model allows the seller to cancel at any time any reservation made earlier, in which case the holder of the reservation incurs a utility loss amounting to a fraction of her value for the reservation and may also receive a cancellation fee from the seller.Our main result is an online mechanism for allocation and pricing in this model with many desirable game-theoretic properties. It is individually rational. Winners have an incentive to be honest and bidding one's true value dominates any lower bid. Further, it bounds the earnings of speculators who are in the game to obtain the cancellation fees. The mechanism in addition has optimization guarantees. Its revenue is within a constant fraction of the a posteriori revenue of the Vickrey-Clarke-Groves (VCG) mechanism which is known to be truthful (in the offline case). Our mechanism's efficiency is within a constant fraction of the a posteriori optimally efficient solution. If efficiency also takes into account the utility losses of bidders whose reservation was canceled, we show that our mechanism matches (for appropriate values of the parameters) an upper bound on the competitive ratio of any deterministic online algorithm.Our mechanism's technical core is a variant of the online weighted bipartite matching problem where unlike prior variants in which one randomizes edge arrivals or bounds edge weights, we may revoke previously committed edges.Our results make no assumptions about bidders' arrival order or value distribution. They still hold if we replace items with elements of a matroid and matchings with independent sets, or if all bidders have additive value for a set of items.
The effect of soil‐particle size on hydrocarbon entrapment near a dynamic water table

Abstract The entrapment of residual hydrocarbon globules by water table fluctuations can produce a long‐term contamination threat to groundwater supplies that is difficult to remove. The mobilization of entrapped hydrocarbon globules depends on the balance between capillary and gravitational forces represented by the Bond number. It is important to estimate the potential for hydrocarbon entrapment at a spill site due to its influence on the effectiveness of remediation efforts. The present work focuses on the influence of particle diameter on hydrocarbon entrapment for a typical LNAPL (light nonaqueous‐phase liquid). Laboratory column tests have been conducted using a dual‐beam gamma densitometer to measure saturations of the three phases (water, air, and hydrocarbon). Soltrol 170®, a solvent manufactured by Phillips 66 Co., is used as the hydrocarbon. Residual saturation of the Soltrol is measured after fluctuations in water table level to establish the distribution and consistency of hydrocarbon entrapm...
The contracted upper midpelvis

Abstract 1. 1. Attention is called to well-known facts which point to the clinical significance of upper midpelvic contractions. 2. 2. Data are presented which show that in contracted pelves the upper midplane is often smaller than the inlet. 3. 3. Evidence is assembled which indicates that the contracted upper midpelvis is an important factor in the etiology of high occipitoposterior arrests, and is a serious obstacle to high midforceps delivery. In a survey of the pelvis, it is therefore necessary to take into consideration the dimensions of the upper midplane as well as the diameters of the inlet and the lower midpelvis. 4. 4. The conclusion is tentatively drawn that cesarean section may often be indicated, even after engagement of the head, in pelves with a contracted inlet in which the upper midplane is smaller than the inlet.
Vision-Based Concussion Testing in a Youth Ice Hockey Cohort: Effects of Age and Visual Crowding (P6.287)

OBJECTIVE: We examined the King-Devick (K-D) test, a vision-based measure of rapid number naming, as a complement to the Sport Concussion Assessment Tool, 3rd edition (SCAT3/Child-SCAT3) for sideline diagnosis in youth athletes. BACKGROUND: Particularly in youth sports, identification of rapid yet simple diagnostic tests for concussion is critical. These rapid tests must be interpreted in the context of developmental status and age. DESIGN/METHODS: Members of a suburban youth ice hockey league participated in a prospective study to examine three brief rink-side tests: K-D test, Standardized Assessment of Concussion (SAC, cognition) and timed tandem gait (balance). To perform the K-D test, athletes read numbers from three laminated test cards from left to right as quickly as possible. The cards become progressively more difficult due to changes in vertical spacing between lines; this is particularly notable for card 3. RESULTS: Ninety-nine athletes (mean age 10.8±3.0 years, range 6-17 years) underwent pre-season baseline testing for this study. Athletes completed the K-D test in an average of 56.5 seconds (best of two baseline trials, range 27.5-159.8 seconds). Average total SAC scores were 26/ maximum 30 points (range 17-30); average best of four trials for timed tandem gait was 15.9±6.0 seconds. All three tests showed better scores among older athletes (p<0.001 for all, linear regression). Time scores for K-D were significantly slower (worse) for younger athletes (p<0.001). This association of worse K-D scores with younger age was most evident for K-D card 3, the card with the greatest degree of vertical visual crowding (average of 3.9 seconds slower vs. card 1, p<0.001, linear regression). CONCLUSIONS: Scores for rapid sideline concussion tests may vary with age and developmental status of youth athletes; better scores in this cohort were noted among older players. Visual crowding, an age-dependent inability to perceive objects due to clutter, may in part explain the more dramatic association of slower time scores on test card 3 with younger age for the K-D test. Disclosure: Dr. Morganroth has nothing to disclose. Dr. Galetta has received personal compensation for activities with Biogen Idec, Questcor, and Teva Neuroscience. Dr. Balcer has received personal compensation for activities with Biogen Idec, Questcor, Novartis, and Vaccinex.
Base Class Injection

Class hierarchies, though theoretically reusable, have generally not seen much practical reuse in applications, due in part to the inflexibility of the inheritance relationship. We present a technique, base class injection, that allows the creation of generative class hierarchies that may be adapted by adding new methods, data members, and ancestor classes without modification to the class library code; an implementation of this technique in the C++ language is given.
Lethal effects of gamma radiation upon segments of a natural microbial population.

One aspect of radiation biology which has received scant attention is the effect of radiations upon natural populations. There is a possibility that such populations may be exposed to such influences in the future; namely, from the release of radioactive wastes in a large scale nuclear power program. Therefore, it seemed desirable to start accumulating basic data on the effects of known dosages of radiation upon natural populations in their native substrate. This paper deals with the lethal effects of gamma radiation upon segments of a natural microbial population, an experiment which is part of an overall ecological study on an entire natural population. 18 references, 1 figure, 3 tables.
Atomistic Modeling in Study of Polymer Electrolyte Fuel Cells – A Review

Polymer electrolyte fuel cell (PEFC) is considered as one of the most promising power sources for futurist’s hydrogen economy. As shown in Fig. 1, operation of a Nafion-based PEFC is dictated by transport processes and electrochemical reactions at catalyst/polymer electrolyte interfaces and transport processes in the polymer electrolyte membrane (PEM), in the catalyst layers consisting of precious metal (Pt or Ru) catalysts on porous carbon support and polymer electrolyte clusters, in gas diffusion layers (GDLs), and in flow channels. Specifically, oxidants, fuel, and reaction products flow in channels of millimeter scale and diffuse in GDL with a structure of micrometer scale. Nafion, a sulfonic acid tetrafluorethylene copolymer and the most commonly used polymer electrolyte, consists of nanoscale hydrophobic domains and proton conducting hydrophilic domains with a scale of 2–5 nm. The diffusivities of the reactants (O2, H2, and methanol) and reaction products (water and CO2) in Nafion and proton conductivity of Nafion strongly depend on the nanostructures and their responses to the presence of water. Polymer electrolyte clusters in the catalyst layers also play a critical role in the catalysis of the nano-sized Pt catalysts. Electrochemical reactions occur at the interfaces between catalysts (Pt or Pt/Ru) and Nafion. The catalytic activity of the Pt catalysts is believed to be dictated by transport processes, adsorption/desorption, and charge transfer in the interfacial area. While transport processes may occur in an area of a few nanometers, adsorption/desorption and charge transfer occur within a region of a few angstroms from the surface of a nano-particulate catalyst. Thus, modeling or simulation of PEFC is a multiscale problem.
Rationally Connected Varieties and Fundamental Groups

The Lefschetz hyperplane theorem says that if X ⊂ ∙ N is a smooth projective variety over ℂ and C ⊂ X is a smooth curve which is a complete intersection of hyperplanes with X then $$ \pi _1^{top}\left( C \right) \to \pi _1^{top}\left( X \right) $$ (1.1) is surjective, where \( \pi _1^{top} \) is the topological fundamental group. Later a quasiprojective version of this result was also established (see, for instance, [13] for a discussion and further generalizations). This says that if X 0 ⊂ X is open and C ⊂ X as above is sufficiently general, then $$ \pi _1^{top}\left( {C \cap {X^0}} \right) \to \pi _1^{top}\left( {{X^0}} \right) $$ (1.2) is surjective.
Privacy and the Regulation of the New Reproductive Technologies: A Decision-Making Approach

This chapter maps out the territory that must be explored in this very complex area and analyzes the implications of governmental regulation of the new reproductive technology. It suggests that the central issue for analysis is the extent to which authority to make decisions concerning reproductive potential should be allocated to individuals rather than to the government. The chapter describes approaches to allocating decision-making authority with respect to procreative issues. The first is a rights-based approach which emphasizes individual autonomy; this approach will not permit governmental regulation which interferes with personal autonomy in decision making, at least without good reason. The second approach accepts regulation which impinges on individual decision making for the public good. The chapter concludes that the problems associated with separate spheres can be minimized if the analysis focuses precisely on the application of the new reproductive technology and on the impact of individual autonomy on women and society.
Models in science and mental models in scientists and nonscientists

This paper examines the form of mental representation of scientific theories in scientists and nonscientists. It concludes that images and schemas are not the appropriate form of mental representation for scientific theories but that mental models and perceptual symbols do seem appropriate for representing physical/mechanical phenomena. These forms of mental representation are postulated to have an analogical relation with the world and it is this relationship that gives them strong explanatory power. It is argued that the construct of naive theories as used in developmental psychology may be the appropriate form of mental representation for non physical/mechanical domains. The paper adopts a strong form of psychologism in the philosophy of science and argues that model-based approaches to scientific theories are more appropriate forms of representation for scientific theories than the formalist approaches that dominate current philosophy of science.
On the Possibility of Observing Negative Fluorescence Dips in Laser-Induced Fluorescence Experiments

Some theoretical considerations are given which show how a negative fluorescence dip (i.e., an increase in the monitored fluorescence signal) can be obtained when one is performing two-step excitation experiments in atmospheric pressure atomizers. Such an inverted dip is due to an increased population of the fluorescent level, caused by cascade de-excitation, both radiational and collisional, from the upper level(s) reached with the second excitation step. No coherence effects are involved. These considerations are supported by the experimental observation of the inverted dip in the stepwise, nonresonance fluorescence of silver atoms present in an inductively coupled argon plasma.
Noise radiation directivity from a wind-tunnel inlet with inlet vanes and duct wall linings

The acoustic radiation patterns from a 1/15th scale model of the Ames 80- by 120-Ft Wind Tunnel test section and inlet have been measured with a noise source installed in the test section. Data were acquired without airflow in the duct. Sound-absorbent inlet vanes oriented parallel to each other, or splayed with a variable incidence relative to the duct long axis, were evaluated along with duct wall linings. Results show that splayed vans tend to spread the sound to greater angles than those measured with the open inlet. Parallel vanes narrowed the high-frequency radiation pattern. Duct wall linings had a strong effect on acoustic directivity by attenuating wall reflections. Vane insertion loss was measured. Directivity results are compared with existing data from square ducts. Two prediction methods for duct radiation directivity are described: one is an empirical method based on the test data, and the other is a analytical method based on ray acoustics.
Effect of initial gamma prime size on the elevated temperature creep properties of single crystal nickel base superalloys

The influence of initial γ′ size and shape on the high temperature creep properties of two single crystal nickel-base superalloys was investigated. The two alloys were chosen to represent different magnitudes of γ-γ′ lattice mismatch. A range of initial microstructures was produced by various quenching and aging treatments. Creep-rupture testing at 1000 °C was performed under stresses where γ′ directionally coarsens to form γ-γ′ lamellae in the early portion of the creep life. Both alloys exhibited a peak in creep resistance as a function of initial γ′ size. The peak corresponded to an initial microstructure consisting of cuboidal precipitates aligned along [001] directions. These aligned cuboidal γ′ particles directionally coarsened into a relatively perfect lamellar γ-γ′ structure in the early stages of creep, whereas the more irregularly shaped and distributed γ′ particles in both under and overaged material formed more irregular lamellae with more imperfections. The alloy with a lower magnitude of mismatch was less sensitive to initial γ′size and shape.
Synthesis and thin-film orientation of poly(styrene-block-trimethylsilylisoprene)

The successful synthesis, characterization, and directed self-assembly of a silicon-containing block copolymer, poly(styrene-block-trimethylsilylisoprene) (P(S-b-TMSI)), which has much higher oxygen etch contrast than the de facto standard, poly(styrene-block-methyl methacrylate) is reported. A Sakurai, Grignard-type coupling reaction provided the key monomer in good yield. Living anionic polymerization was employed to prepare the block copolymer, which has very low polydispersity. P(S-b-TMSI) was successfully ordered and oriented by directed self-assembly. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Random generations of the countable random graph

Abstract We consider random processes more general than those considered by Erdos and Renyi for generating the countable random graph. It is proved that, in the category sense, almost all random processes we consider generate the countable random graph with probability 1. Under a weak boundedness assumption we give a criterion for the random processes which generate the countable random graph almost surely. We also consider further questions asked by Jackson regarding the outcome graphs when the process fails to produce the countable random graph.
Sustainability and gold mining in the developing world

Abstract Generally, the gold mining industry has a negative image because it is potentially highly polluting, its costs often externalized on local communities that host its operations. Recently, there has been growing activism in most countries where rich gold deposits exist. Although the industry has many drawbacks, it can potentially confer many benefits, especially for the people of the developing world, by providing employment and foreign exchange. In the context of the mining sustainable development debate, this paper examines the environmental performance of the gold mining industry in developing countries, and its impacts on resident populations and communities.
A collaborative approach in workforce assessment: South Carolina's strategies for high response rates.

The South Carolina Public Health Training Center and South Carolina Department of Health and Environmental Control conducted a state public health workforce assessment using a collaborative methodology. A joint workforce assessment team used the 2010 Core Competencies for Public Health Professionals—developed by the Council on Linkages Between Academia and Public Health Practice—as the basis for the assessment and resulting continuing education programs. A 91% response rate (n = 1,375) was achieved among full-time regional employees, while an 81% response rate (n = 1,598) was achieved among all regional employee types. This unusually high response rate in a voluntary assessment was accomplished by involving key stakeholders in the planning, development, and implementation process and by communicating directly with leaders in South Carolina’s eight health regions. In addition to boosting the response rate, the collaborative approach strengthened the partnership between the academic and practice partners. I...
Instabilities in hot nuclear matter and the fragmentation process

Abstract Fragmentation in heavy-ion collisions is studied theoretically by examining the conditions under which density fluctuations may grow during the expansion of a sphere of heated or superdense nuclear matter. Matter is described by the realistic equation of state of Friedman and Pandharipande. The growth rates and accumulated growth factors depend sensitively on the wavenumbers of the fluctuations. Growth rates are examined in the limiting regimes of hydrodynamic and of collisionless motion, and the effects of viscous damping and thermal conduction are also considered.
Interaction of PAH-related compounds with the α and β isoforms of the estrogen receptor

The ability of several 4- and 5-ring polycyclic aromatic hydrocarbons (PAHs), heterocyclic PAHs, and their monohydroxy derivatives to interact with the estrogen receptor (ER) alpha and beta isoforms was examined. Only compounds possessing a hydroxyl group were able to compete with 3H-labeled 17beta-estradiol (E2) for binding to either a glutathione-S-transferase and human ERalpha D, E, and F domain fusion protein (GST-hERalphadef) or to the full-length human ERbeta. Competitive binding was comparable for both isoforms, with IC(50) values ranging from 20 to 300 nM (E2 IC(50) approximately 3 nM). However, several compounds were able to induce reporter gene expression preferentially through mERbeta, using MCF-7 cells transiently transfected with either a Gal4-human ERalphadef or Gal4-mouse ERbetadef construct, as well as a Gal4-regulated reporter. These data extend the number and type of PAH-related compounds capable of interacting with ERalpha and ERbeta, and provides additional evidence that even though some compounds may possess a similar affinity for both ER isoforms, the capacity for transcriptional activation can still be isoform-specific.
Useful representations of series solutions for transport problems

Simple techniques are presented for rearrangement of an infinite series in a systematic way such that the convergence of the resulting expression is accelerated. These procedures also allow calculation of required boundary derivatives. Several examples of conduction and diffusion-reaction problems illustrate the methods.
‘‘We Don’t Talk to Terrorists’’: On the Rhetoric and Practice of Secret Negotiations

Political actors sometimes make public commitments not to negotiate with adversaries whom they label as being beneath diplomacy. Such commitments are sometimes made even as they are being broken. Why do actors sometimes publicly denounce adversaries with whom they intend to negotiate? What effect does such prenegotiation rhetoric have on the prospects for successful negotiated settlements? In this paper, the authors present a novel game-theoretic model of conflict bargaining, in which actors can make public commitments not to negotiate before deciding whether to engage in secret negotiations with adversaries. The authors model such commitments as affecting actors’ audience costs; a denunciation increases an actor’s motivation to reach a negotiated settlement if negotiations are undertaken. Although such a decision weakens an actor’s bargaining power, in equilibrium actors sometimes publicly denounce their counterparts. The authors present and interpret equilibrium behavior in their model and discuss the implications of their results for future research.
Simulated Response of the Atmosphere-Ocean System to deforestation in the Indonesian Archipelago

The climatic effects of large-scale deforestation in the Indonesian Archipelago are investigated using a fully coupled atmosphere-ocean model— the Fast Ocean Atmosphere Model (FOAM). Extremely rapid rates of deforestation across the Archipelago motivate this study. We compare two simulations (one with fixed ocean temperatures, another where the ocean responds to changing atmospheric conditions), to investigate the potential for oceanic feedbacks on deforestation-induced climate change. With fixed sea surface temperatures, evaporation decreases over land but increases over the surrounding oceans where the wind speeds increase. Regional deep convection is enhanced and precipitation increases over the islands. With an interactive ocean the initial decrease in evaporation over the deforested land reduces convergence and increases the easterlies in the Bay of Bengal. More intense equatorial upwelling cools the surface temperatures over that region and reduces ocean evaporation. Regional convection is less intense and precipitation drops by 9% over deforested land.
Rheological investigations of suspensions of talc, calcium carbonate, and their mixtures in a polystyrene melt

An experimental study of the rheological properties of talc, calcite, and mixed particle compounds of polystyrene (PS) compounds has been carried out on a range of instruments at 200°C. We investigated the shear viscosity over a very wide range of shear rates in capillary, cone-plate, and sandwich rheometers. Shear stresses below which there is no flow, i.e. yield stresses, were found. A uniaxial elongational rheometer based on floating samples on a silicone oil bath was used to study the uniaxial extensional flow characteristics. The compounds were found to absorb silicone oil. It was, however, possible to estimate yield values of highly filled compounds in uniaxial extension by investigating the stretching of vertical filaments in a chamber filled with nitrogen.
Integrated Genomic Analysis of Nodular Tissue in Macronodular Adrenocortical Hyperplasia: Progression of Tumorigenesis in a Disorder Associated with Multiple Benign Lesions

Integrated transcriptomic and genomic data for AIMAH provides supporting evidence that larger adrenal nodules accumulate an increased number of genetic, and consequently, transcript abnormalities.
Race and sex differences in head size and IQ

Abstract An analysis of IQ in relation to head size (and by inference, brain size) was performed on some 14,000 children and their full siblings, almost evenly divided by race (white and black) and sex, on whom data were obtained at ages 4 and 7 years in the National Collaborative Perinatal Project. Within each race × sex group, IQ is significantly correlated with head size, age and body size having been partialed out. A significant positive correlation between IQ × head size exists not only within subjects (at ages 4 and 7) but also within families and between families (at age 7 only). The within-families correlation (at age 7) is consistent with an intrinsic or pleiotropic correlation between the mental and physical variables. No significant positive correlation within families appeared at age 4, despite a significant within-subjects correlation at that age. As yet, there are only speculative explanations of the disparity between the age 4 and 7 within-family correlations of head size with IQ. Although general body size is also correlated with IQ within subjects and between families, the correlation does not exist within families in either age group, which rules out a pleiotropic correlation between body size and IQ. There are both race and sex differences in head size, although the sex difference in IQ is nil. White and black children who are matched on IQ show, on average, virtually zero difference in head size.
Quarkonium dissociation in quark-gluon plasma via ionization in a magnetic field

We study the impact of magnetic fields generated in relativistic heavy ion collisions on the decay probability of quarkonium produced in the central rapidity region. The quark and anti-quark components are subject to mutually orthogonal electric and magnetic fields in the quarkonium comoving frame. In the presence of an electric field, quarkonium has finite dissociation probability. We use the WKB approximation to derive the dissociation probability. We found that quarkonium dissociation energy, i.e. the binding energy at which dissociation probability is of order unity, increases with the magnetic field strength. It also increases with quarkonium momentum in the laboratory frame due to Lorentz boost of electric field in the comoving frame. As a consequence, J/Psi in plasma dissociates at lower temperature then it would be in the absence of a magnetic field. We argue that J/Psi's produced in heavy-ion collisions at LHC with P_T>9GeV would dissociate even in vacuum. In plasma, J/Psi dissociation in magnetic field is much stronger due to decrease of its binding energy with temperature. We discuss the phenomenological implications of our results.
Inhibition of nitric oxide generation and lipid peroxidation attenuates hemolysate-induced injury to cerebrovascular endothelium.

The mechanisms of hemolysate-induced cerebral injury following subarachnoid hemorrhage are just beginning to be clarified. This study examined the injurious effects of hemolysate on endothelial cells derived from bovine middle cerebral arteries, and evaluated the roles of lipid peroxidation and nitric oxide production in this type of damage. Cultured endothelial cells were grown to confluency on gelatin-coated plates. The cells were characterized as endothelial cells on the basis of morphology, Factor VIII-related antigen staining, and low density lipoprotein (LDL) uptake. Additional cells were grown to confluency on collagen-coated well inserts, and were treated with hemolysate for 24 hours. Prior to hemolysate exposure, cells were treated with: a) an inhibitor of iron-dependent lipid peroxidation (tirilazad mesylate 100 μM), or b) an inhibitor of nitric oxide synthase (either N-nitro-L-arginine: NLA 300 μM, or aminoguanidine: AG at 1.5, 7.5, 15 or 150 μM). Permeability of the tracer, U-14C-sucrose, across the layer of endothelial cells was examined over a 24 hour period. Hemolysate induced a significant increase in the permeability across the endothelial cell layer. Pretreatment with tirilazad mesylate, NLA, or AG attenuated significantly hemolysate-induced changes in the endothelial cell barrier.
Mo/Rh Carboxylate: Heterometallic Compound Built of Homometallic Paddlewheel Units

Mixed-metal molybdenum(II)/rhodium(II) tetra(trifluoroacetate) of the composition [(MoRh)(O2CCF3)4] has been obtained from the gas-phase reaction between volatile carboxylates, [Mo2(O2CCF3)4] and [Rh2(O2CCF3)4]. This is an interesting system for which a single-crystal X-ray investigation fails to provide an unambiguous evidence of whether the product consists of the initial homometallic or newly formed heterometallic paddlewheel units. In the solid-state structure both metal atoms occupy the same crystallographic position, while the M−M and M−O distances are averaged with respect to the parent homometallic compounds. Nevertheless, the results of mass-spectrometric and magnetic measurements clearly indicate that the title bimetallic carboxylate contains a statistical mixture of homometallic dimolybdenum and dirhodium units. The product can be considered as a result of cocrystallization of isomorphous paddlewheel molecules.
Magnetic excitations in the sinusoidal spin phase of Er and Tm

The frequency moment method is used to study the magnetic excitations in magnetically ordered systems, especially the sinusoidally modulated spin structure that occurs just below the N{acute e}el temperatures of erbium and thulium. It is shown that the transverse excitations may have rather sharp but dispersionless spectra or broad spectra depending on the relative strengths of the twofold anisotropy energy versus the exchange energy. The longitudinal spin excitations are extensions of the Goldstone modes. They may have rather sharp spectra with linear dispersion relations when the exchange and anisotropy energies are comparable. {copyright} {ital 1996 The American Physical Society.}
Moral and Legal Perspectives on Palestine: a Review Essay

Book reviewed in this article: Speaking the Truth: Zionism, Israel, and Occupation: by Michael Prior, ed.; foreword by Archbishop Desmond Tutu The Case for Palestine: an International Law Perspective: by John Quigley Palestinians Born in Exile: Diaspora and the Search for a Homeland: by Juliane Hammer
A General Mechanism for Stabilizing the Small Sizes of Precious Metal Nanoparticles on Oxide Supports

We recently discovered that MgAl2O4 spinel (111) nanofacets optimally stabilize the small sizes of platinum nanoparticles even after severe high-temperature aging treatments. Here we report the thermal stabilities of other precious metals with various physical and chemical properties on the MgAl2O4 spinel (111) facets, providing important new insights into the stabilization mechanisms. Besides Pt, Rh, and Ir can also be successfully stabilized as small (1–3 nm) nanoparticles and even as single atomic species after extremely severe (800 °C, 1 week) oxidative aging. However, other metals either aggregate (Ru, Pd, Ag, and Au) or sublimate (Os), even during initial catalyst synthesis. On the basis of ab initio theoretical calculations and experimental observations, we rationalize that the exceptional stabilization originates from the epitaxially matched structure, i.e., lattice matching in geometry and the correspondingly strong electronic attractions at interfaces between the spinel (111) surface oxygens and...
Enhanced Visible‐Light Photocatalytic Disinfection of Bacterial Spores by Palladium‐Modified Nitrogen‐Doped Titanium Oxide

Palladium-modified nitrogen-doped titanium oxide (TiON/PdO) nanofibers were synthesized by a sol–gel process on activated carbon-coated glass fiber (ACGF) template. The TiON/PdO fiber was tested for visible-light-activated photocatalysis using Bacillus subtilis endospore as a target. Our work shows that TiON/PdO nanofibers display an effective antimicrobial effect on Bacillus spores. The palladium modification provides a strong enhancement over TiON in the photocatalytic disinfection. Microscopic characterization demonstrated that visible-light photocatalysis on TiON/PdO fiber caused drastic damage on the spore coat and internal structure.
Spin dynamics in magnets: Equation of motion and finite temperature effects.

General equations of motion are introduced for the evaluation of spin dynamics in magnetic materials. The theory uses the adiabatic separation of diagonal and off-diagonal components of the spin density matrix. This adiabatic approach considers the orientation of the local magnetic moments to be slowly varying relative to their magnitudes. The angles of the magnetization density are introduced as collective variables in density functional theory. The equations and technique can be simultaneously combined with those of first-principles molecular dynamics for the consistent treatment of spin-lattice interactions. Stochastic and deterministic approaches for treating finite temperature effects are introduced for such dynamics. The method is implemented within the local density approximation and applied to \ensuremath{\gamma}-Fe, a frustrated system where we obtain additional low-energy magnetic configurations. \textcopyright{} 1996 The American Physical Society.
Body mass index and the risk of postoperative complications with dentoalveolar surgery: A prospective study

Objectives Obesity is a disease that affects millions of Americans. Sixty-nine million Americans are considered to be overweight including at least 1 in 5 children. Overweight and obesity as risk factors for complications associated with dentoalveolar surgery have not been extensively studied. The purpose of this study was to prospectively investigate the frequency and the nature of postoperative complications in obese patients receiving ambulatory dentoalveolar surgery. Study design Patients undergoing dentoalveolar outpatient ambulatory surgery at the University of Cincinnati Oral and Maxillofacial Surgery Clinic from January 10, 2005 to December 7, 2005 were enrolled in a prospective study. At the preoperative visit, height, weight, and age were recorded. The body mass index (BMI) was calculated and patients were divided into weight categories based on CDC and WHO classifications. Unfavorable outcomes studied included number of postoperative visits, infections, alveolar osteitis, soft and hard tissue problems, and postoperative bleeding. Complication categories were created for all complications identified during postoperative exams and t tests were performed to see if increased BMI correlated to higher postoperative complication rates, if multiple complications correlated to increased BMI, and to see if individual postoperative complication groups and BMI correlated. Because it was thought that complications would increase the number of postoperative exams for a particular patient, simple linear regression was used to see if BMI correlated to increased number of postoperative visits. Results No significant differences were noted in number of postoperative complications when comparing patients' BMIs (t = −0.62, P = .5350). Simple linear regression analysis showed that increased BMI did not predict increased number of postoperative visits. Increased age was the only predictor of increased postoperative complication risk (t = −3.17, P = .0016) and of increased number of postoperative visits (t = −16.35, P < .0001, and P < .0001 by nonparametric Wilcoxon rank sum test). Conclusions The BMI is not statistically correlated to higher postoperative complication rates or increased number of postoperative visits. Obesity remains an important risk factor for dentoalveolar ambulatory outpatient anesthesia; however, it is not associated with poorer postoperative complication rates.
Beyond the satire: Selective exposure and selective perception in “In Living Color”

This study uses selective exposure and selective perception theories to analyze both the viewership and the reaction to ‘In Living Color.”; Created, produced, and directed by an African American, this controversial prime‐time satire uses traditional racial stereotypes to look at the African American community. Two studies were conducted to test the selective exposure and perception hypotheses. In the first study, a survey was used to measure viewership and reaction to the program. The second study used focus groups to explore perceptions of the show in more depth. Several themes concerning the show (negative stereotyping, potential for learning about African American culture, reality vs. parody, comparison to similar shows, and economic vs. societal value of the show) are presented and discussed.
Atomic layer epitaxy of InP using trimethylindium and tertiarybutylphosphine

Abstract Atomic layer epitaxy (ALE) growth of InP was investigated using trimethylindium (TMI) and tertiarybutylphosphine (TBP) in a horizontal atmospheric reactor. The studied growth parameters were exposure times, TMI and TBP fluxes, and growth temperature. Self-limiting ALE growth of InP was achieved at a growth temperature of 340°C. Substantial increases in the TMI flux and higher growth temperatures exceeding 340°C resulted in growth rates exceeding 1 monolayer per cycle. Uniform ALE InP layers were verified by cross-sectional transmission electron micrography and sputtered Auger profiling. The application of thin ALE InP layers (15 A) on GaAs surfaces was investigated using X-ray photoelectron spectroscopy, 77 K photoluminescence, and 300 K photoreflectance. The absence of arsenic oxide and an increase in the photoluminescence intensity by a factor of 2 were observed after InP passivation.
The effect of fluid elasticity on power consumption and mixing times in stirred tanks

Abstract Results are presented to show the effects of fluid elasticity on the power required for mixing and the time necessary to obtain a certain degree of homogenization (i.e. mixing time) in the viscous regime. To separate the effects of elasticity from those of shear thinning viscosity, elastic fluids with constant viscosities are used. Experiments in baffled tanks with Rushton turbine impellers show that elastic fluids require more power than inelastic fluids having equal viscosities. A correlation for the increased torque required to agitate an elastic fluid is presented that has a form suggested by the analytical solution for the effect of elasticity on the torque required to spin a sphere in a second-order elastic fluid. Elasticity also increases mixing time. Mixing time measurements are made using three probes at different locations in the vessel. The probes, based on fiber-optic sensors, detect a fluorescent dye tracer at the parts per billion concentration level.
Mass extinctions of life and catastrophic flood basalt volcanism

Extinctions have played an important role in the history of life by clearing out niches and fostering adaptive radiations. Major mass extinctions involving 70% to more than 90% of extant species occurred at least five times during the last 540 million years. The discovery by Alvarez et al. (1) that the end-Cretaceous (65 Mya) mass extinction coincided with evidence for the impact of an asteroid or comet ∼10 km in diameter focused interest in the causes of the other mass extinctions. It was expected that evidence of a similar impact might be found at other mass extinction events. Such evidence, however, has been slow in coming (2). At the same time, episodic massive continental flood basalt eruptions were suggested as another possible cause of mass extinctions (3, 4). This connection is illustrated by a study by Whiteside et al. (5) that provides evidence that the eruption of the Central Atlantic magmatic province (CAMP) basalts, with a preserved volume greater than 1 × 106 km3 and covering more than 7 × 106 km2, coincided with the end-Triassic extinction event (ETE) (201.4 Mya) on land and in the oceans.
Commercializing biomedical research through securitization techniques

The authors propose that the increasing risk of biopharma investing can be reduced through megafunds that support many biomedical programs and attract investment from large institutions such as pension funds. Biomedical innovation has become riskier, more expensive and more difficult to finance with traditional sources such as private and public equity. Here we propose a financial structure in which a large number of biomedical programs at various stages of development are funded by a single entity to substantially reduce the portfolio's risk. The portfolio entity can finance its activities by issuing debt, a critical advantage because a much larger pool of capital is available for investment in debt versus equity. By employing financial engineering techniques such as securitization, it can raise even greater amounts of more-patient capital. In a simulation using historical data for new molecular entities in oncology from 1990 to 2011, we find that megafunds of $5–15 billion may yield average investment returns of 8.9–11.4% for equity holders and 5–8% for 'research-backed obligation' holders, which are lower than typical venture-capital hurdle rates but attractive to pension funds, insurance companies and other large institutional investors.
The impact of an occluded internal carotid artery on the mortality and morbidity of patients undergoing coronary artery bypass grafting.

Purpose: To evaluate whether the presence of stenosis or an occluded internal carotid artery (ICA) influences perioperative stroke and mortality rates in patients subjected to coronary artery bypass grafting (CABG). Material andmethods: Between January 1995 and July 1998, 3,344 patients (59% males; 41% females) had CABG performed at our institution. Preoperative carotid duplex scans performed by registered vascular technologists at an ICAVL accredited laboratory were available for review in all patients. Of these, 3,101 (92.7%) had <60% ICA stenosis (group A), 182 (5.4%) had 60% to 99% ICA stenosis (group B), and the remaining 61 (1.8%) had a occluded ICA (group C). In the latter group, 53 patients (87%) had <60% contralateral ICA stenosis, while 8 (13.1%) had significant (60% to 99%) contralateral stenoses. Concomitant carotid endarterectomies (CEAs) were performed in 70 patients in group B (40%) and in 2 patients in group C (3.2%). Age, indications for surgery, prevalence of diabetes, hypertension, and smoking were similar in all groups. The mean pump time for groups A, B and C were 132, 138, and 125 minutes, respectively. The aortic cross-clamp time for group A, B, C were 78, 75, and 75 minutes, respectively. Statistical analyses were performed using the chi-square, Fisher’s exact test, and unpaired t test. Results: Perioperative stroke rates (30 days) were 1.6%, 3.8%, and 6.5% for groups A, B, and C, respectively. Group A results varied significantly from groups B (P <0.03) and C (P <0.003). No statistically significant difference was noted between groups B and C (P = 0.6). The presence of a contralateral ICA stenosis in group C patients was predictive of a perioperative stroke (25% versus 3.8%; P <0.0001). Concomitant CEAs for contralateral severe ICA stenosis in group C were associated with higher stroke rate (100%) when compared with those in group B patients (4.2%; P <0.02). Perioperative (30 days) mortality rates for groups A, B, and C were 3.6%, 6.6%, and 8.6%, respectively. The mortality rate for group A was lower than for groups B (P <0.05) and C (P <0.05). Conclusion: The presence of an ICA occlusion increases the morbidity and mortality in patients undergoing CABG. To the best of our knowledge, this is the first reported large series of patients that investigates the role of carotid occlusions.