cssi/SciSciGPT-SciSciNet huggingface dataset:
PCG solutions of flow problems in random porous media using mixed finite elements

Abstract The behavior of preconditioned conjugate gradient (PCG) solutions of flow problems in random porous media is examined. The flow problems are discretized with the mixed finite element method, the resulting matrix is reduced in size by block Gauss elimination, and PCG is applied to the resulting problem. As a result of the matrix reduction and the need to store the resultant matrix implicitly because of storage limitations for large problems, the selection of a preconditioner is not obvious. Four heuristic preconditioners, selected because of the simplicity with which they can be constructed from the implicit matrix representation and because of their potential for high performance computers, are tested: diagonal, tridiagonal, scaled diagonal, and scaled tridiagonal. Tests on fields with random hydraulic conductivity, with both isotropic and anisotropic correlation functions and with a large range of standard deviations, are performed. The scaled tridiagonal and diagonal preconditioners prove very effective and efficient for a broad range of problems, even for conductivity variations of 25 orders of magnitude.
Complexity of path traffic grooming

Feature Issue on Transmission in Optically Transparent Core NetworksThe problem of efficiently designing lightpaths and routing traffic on them in hybrid electro-optic data communication networks so that optical pass-through is maximized and the electronic switching cost is minimized is known as traffic grooming and has been studied extensively. Traffic grooming is known to be an inherently difficult problem. It has been shown to be NP-complete even for path networks, a simple topology in which lightpath wavelength assignment is tractable. In this paper, we explore the borderline between tractability and intractability by considering grooming in unidirectional path networks in which all traffic requests are destined for a single egress node. Whether the complete grooming problem is NP-hard with this restriction is an open question. We show that at least the problem of routing traffic on a given virtual topology to minimize electronic switching (NP-hard for path networks with arbitrary traffic matrices) becomes polynomial on the egress model. We also show that in the egress model, if the capacity constraint is relaxed, the entire problem becomes polynomial. If, in addition, traffic requests are uniform, we provide an explicit combinatorial formula for the optimum solution as well as an algorithm that constructs a routing that achieves this optimum. For the case of finite capacity and unit traffic requests, we show how to polynomially find a feasible solution that is optimal under reasonable assumptions.
Parametric differentiation revisited

A number of now-ancient texts in advanced calculus employed the method of parametric differentiation to deduce evaluations for a variety of complicated definite integrals (e.g., [4,7]). In his autobiography [3], R. P. Feynman mentioned how he frequently used this approach when confronted with difficult integrations associated with mathematical and physical problems. He referred to that method as "a different box of tools." Most modern texts either ignore the subject or provide only one or two examples to illustrate theorems on the uniform convergence of improper integrals. (See [8] for a more recent treatment of integrals.) However, the method of parametric differentiation has a much broader scope than this. It can, in fact, be introduced into the elementary calculus to simplify the treatment of partial fractions with repeated factors, to carry out integrations ordinarily handled by parts, and to treat integrals that use substitutions. When tied in with other mathematical machinery (e.g., complex variables), it can be used to deduce formulas for special functions and to solve problems in differential equations that involve iterated operators. Finally, the method can be conveniently used in conjunction with mathematical software packages that handle symbolic differentiations. In this note, we give three examples from calculus to illustrate the flexibility of this approach at the elementary level. One of the integrals treated is connected with the t-distribution. We also note, without providing a complete discussion, how this technique can be used to evaluate the Riemann zeta function at 2p, p = 1, 2,.. ., and how it can be used in differential equations. A more extensive set of applications is available from the author. In the work to follow, we call upon the Leibniz product rule for differentiation as well as theorems that permit interchanging orders of differentiation and integration (see [5, 6]). We also need to make frequent use of the formula
Cardiac glucose and fatty acid oxidation in the streptozotocin-induced diabetic spontaneously hypertensive rat.

Abstract Hypertension intensifies the cardiac dysfunction of diabetes. We investigated the possible role of altered exogenous fuel oxidation in this phenomenon. Diabetes was induced by streptozotocin in spontaneously hypertensive rats and normotensive Sprague-Dawley rats. Two weeks later, mechanical performance and the oxidation of glucose and palmitate were quantified in working hearts ex vivo at intermediate and high workloads. The results showed that the nondiabetic spontaneously hypertensive rat hearts, compared with those of the normotensive controls, oxidized glucose at a higher rate but oxidized palmitate at a much lower rate, as reported previously. The effects of diabetes in the hypertensive rats, compared with its effects in the normotensive strain, were characterized by (1) a more pronounced decrease in heart performance, (2) either a similar or a less marked reduction in the rate of glucose oxidation, depending on the workload, and (3) a relatively greater increase in palmitate oxidation, particularly at the higher workload. These findings suggest that the exaggerated stimulation of fatty acid oxidation by diabetes in the hypertrophic left ventricle may be a more important contributor to the premature mechanical dysfunction than the inhibition of glucose oxidation. Possible mechanisms include antagonism of energetically favorable shifts in fuel oxidation or inhibition of accelerated membrane lipid biosynthesis in left ventricular hypertrophy.
Synthesis and Photophysical Properties of Dinuclear Organometallic Rhenium(I) Diimine Complexes Linked by Pyridine-Containing Macrocyclic Phenylacetylene Ligands

Two novel pyridine-containing hexagonal phenylacetylenic macrocyclic ligands have been synthesized from Pd-catalyzed cross-coupling or Cu-catalyzed oxidative coupling reactions. These ligands have been subsequently used to prepare dinuclear 4,4‘-di-tert-butyl-2,2‘-bipyridine Re(I) tricarbonyl complexes. Both ligands and complexes show strong luminescence in room-temperature solution. There is no concentration dependence in the 1H NMR spectra for these ligands and complexes, which rules out ground-state self-association. However, both of the free ligands exhibit concentration-dependent fluorescence. The fluorescence bands of the ligands are red-shifted with increasing concentration, and this behavior is ascribed to the formation of excimers in the excited states. In contrast, both of the organometallic complexes do not exhibit any concentration-dependent luminescence.
Genetically optimized fractile microstrip patch antennas

We introduce a new family of microstrip patch antennas that are based upon fractal tile (i.e., fractile) geometries. We call such antennas fractile microstrip antennas. By utilizing the properties of fractal tiles, it is possible to create single-feed modular designs for microstrip patch antennas with broadside gains that are in excess of 12 dB when they are operated to excite high-order localized modes. Two examples of fractile microstrip patch antenna configurations are presented, namely the fudgeflake and Gosper island microstrip antennas. In the design of these antennas, a genetic algorithm was employed to optimize their performance.
The molecular device computer: Point of departure for large scale cellular automata

Abstract Switching is possible at the molecular size level because of the conformational changes that occur. Three of the most promising switching mechanisms include electron tunnelling in short periodic arrays, soliton switching and soliton valving. Assuming a 3-d architecture and molecular dimensions, memory and switching elements with densities of 10 15 to 10 18 elements per cc are possible. The active elements are connected together conceptionally with “molecular wires” like polysulfur nitride (SN) x and polyacetylene (CH) x . Simple cellular automata involving soliton propagation in conjugated systems would include soliton valves and cyclic configurations of valves. In the latter, soliton propagations becomes isomorphous with group operations giving rise to possible non-binary finite-state machines. The development of a molecular electron device (MED) synthetic capability in combination with the above devices would suggest that large 3-d arrays of parallel processors will be possible with automata, biological, and crystallographic implications.
The Metaphysical Irrelevance of the Compatibilism Debate (and, More Generally, of Conceptual Analysis)

It is argued here that the question of whether compatibilism is true is irrelevant to metaphysical questions about the nature of human decision-making processes—for example, the question of whether or not humans have free will—except in a very trivial and metaphysically uninteresting way. In addition, it is argued that two other questions— namely, the conceptual-analysis question of what free will is and the question that asks which kinds of freedom are required for moral responsibility—are also essentially irrelevant to metaphysical questions about the nature of human beings.
Reversed-phase liquid chromatography and argentation chromatography of the minor capsaicinoids.

An investigation of the liquid chromatography of the minor capsaicinoids in a commercial capsaicinoid mixture is reported. Twelve stationary phases including C8, C18, C30, phenyl, and cation-exchange chemistries were examined in combination with isocratic aqueous methanol and aqueous acetonitrile mobile phases. A phenyl stationary phase and aqueous acetonitrile mobile phase baseline-resolved 7 of 11 capsaicinoids, and selected ion chromatograms (LC–ESI-MS) demonstrated this was the most effective reversed-phase separation. Argentation chromatography with an alkyl or phenyl column and aqueous silver nitrate–methanol mobile phase revealed the presence of the 6-ene-8-methyl and 6-ene-9-methyl homocapsaicin isomers and the absence of 7-ene-9-methyl homocapsaicin. A mixed phenyl–cation-exchange stationary phase (charged with silver ion) enabled unique and useful separations of the capsaicinoids.
The origin of Bahamian Whitings revisited

Two schools of thought exist regarding the origin of the aragonite needles which make up the milky patches of water prominent on the Bahama Banks. One school views these so-called whitings as spontaneous precipitates [Cloud, 1962; Shinn et al.,1989; Robbins et al.,1997] and the other views them as stirred up bottom sediment [Broecker and Takahashi, 1966; Morse et al.,1984]. In the paragraphs which follow we summarize what we consider to be iron-clad radiocarbon and chemical evidence that whitings are dominated by re-suspended sediment. We offer a new and highly speculative mechanism for this re-suspension. Black-tipped sharks which inhabit whitings purposefully stir up the sediment in order to create a trap for fish, much as spiders construct webs as traps for insect prey.
EPR SPECTRA OF PEROXY RADICALS IN IRRADIATED ORIENTED POLYTETRAFLUOROETHYLENE

Abstract The electron paramagnetic resonance (EPR) spectra given when polytetrafluoroethylene (PTFE) samples previously irradiated in vacuum are exposed to air, or when PTFE samples are irradiated directly in air have been known since 1955 and are attributed to peroxy radicals. Little attention, however, has been paid to the details of these spectra. EPR measurements at 77°K and 296°K on oriented PTFE samples irradiated in vacuum and then exposed to air are reported. At 77°K, the spectral line shapes can be understood assuming that the radicals are essentially stationary and have an axially symmetric g -tensor with g ∥ = 2.04 and g ⊥ = 2.002. These values are compared with those of other radicals in which the unpaired electron is thought to be located mainly on an oxygen atom. At 296°K, the spectra are narrower, showing the occurrence of motion. This is probably an oscillation about the polymer chain axis.
Symplectic structure of the collective manifold.

We consider the symplectic structure of the collective manifold as it emerges in a path integral approach. We make use of the Hubbard-Stratonovich transformation in order to integrate out the fermionic degrees of freedom. The effective action obtained in this way is expressed in terms of the single-particle components of the one-body density or potential, which play the role of phase space variables. We show that the term usually designed as the quantum nonintegrable phase is the only term responsible for the definition of the symplectic structure on this manifold. Without this term the Poisson bracket on the collective manifold is undefined.
Radio Interference from Insulator Corona

Extended laboratory tests reveal that the corona formation voltage and the initial radio interference voltage of clean, dry insulators are identical. Oscillograms show many interesting characteristics of insulator corona current and of the radio interference caused by it. Means for reducing the interference are suggested.
Estimating the Mean Diapycnal Mixing Using a Finescale Strain Parameterization

AbstractFinescale methods are currently being applied to estimate the mean turbulent dissipation rate and diffusivity on regional and global scales. This study evaluates finescale estimates derived from isopycnal strain by comparing them with average microstructure profiles from six diverse environments including the equator, above ridges, near seamounts, and in strong currents. The finescale strain estimates are derived from at least 10 nearby Argo profiles (generally <60 km distant) with no temporal restrictions, including measurements separated by seasons or decades. The absence of temporal limits is reasonable in these cases, since the authors find the dissipation rate is steady over seasonal time scales at the latitudes being considered (0°–30° and 40°–50°). In contrast, a seasonal cycle of a factor of 2–5 in the upper 1000 m is found under storm tracks (30°–40°) in both hemispheres. Agreement between the mean dissipation rate calculated using Argo profiles and mean from microstructure profiles is wi...
The surgical management of ossification of the posterior longitudinal ligament in 51 patients.

Summary:Ossification of the posterior longitudinal ligament (OPLL) in the cervical spine warrants unique clinical, radiographic, and surgical management. OPLL patients presenting with severe myelopathy require full assessment with both magnetic resonance imaging (MRI) and computed tomography-based (
An algorithm for segmentation of metaphase spreads

Abstract An algorithm is proposed for locating chromosomes in photomicrographs of metaphase spreads. The algorithm resembles closely the method used by human operators to search microscopic fields. The algorithm was specially programmed to be used with small scale computers.
In-situ electron microscopy studies of surface segregation in bimetallic catalyst particles

Abstract We have used various techniques including in-situ transmission electron microscopy to examine the manner by which the catalytic action of platinum is modified by the introduction of either iron, cobalt, or nickel into the metal. Changes in the behavior of the noble metal have been investigated by the use of the probe reactions, catalytic oxidation, and hydrogenation of single-crystal graphite, which are known to be extremely sensitive to the chemical state of the catalyst surface. In-situ electron diffraction measurements showed that in all cases alloys were formed when the mixed system was treated in hydrogen. When such specimens were subsequently heated in oxygen the composition and chemical state of the particles changed significantly, the ferromagnetic metal tending to segregate to the catalyst-gas interface in the form of an oxide leaving platinum and residual alloy at the graphite interface. Under these conditions the catalyst was observed to undergo a spreading action along the graphite edge regions and it was interesting to find that in this bimetallic state there was a significant decrease in the catalytic activity of the noble metal toward graphite oxidation.
Kosmochloric Ca-rich pyroxenes and FeO-rich olivines (Kool grains) and associated phases in Stardust tracks and chondritic porous interplanetary dust particles: Possible precursors to FeO-rich type II chondrules in ordinary chondrites

Terminal particles and mineral fragments from comet 81P/Wild 2 were studied in 16 aerogel tracks by transmission and secondary electron microscopy. In eight tracks clinopyroxenes with correlated Na2O and Cr2O3 contents as high as 6.0 wt% and 13.0 wt%, respectively, were found. Kosmochloric (Ko) clinopyroxenes were also observed in 4 chondritic interplanetary dust particles (IDPs). The Ko clinopyroxenes were often associated with FeO-rich olivine ± Cr-rich spinel ± aluminosilicate glass or albitic feldspar, assemblages referred to as Kool grains (Ko = kosmochloric Ca-rich pyroxene, ol = olivine). Fine-grained (submicron) Kool fragments have textures suggestive of crystallization from melts while coarse-grained (>1 μm) Kool fragments are often glass-free and may have formed by thermal metamorphism in the nebula. Average major and minor element distributions between clinopyroxenes and coexisting FeO-rich olivines are consistent with these phases forming at or near equilibrium. In glass-bearing fine-grained Kool fragments, high concentrations of Na in the clinopyroxenes are inconsistent with existing experimentally determined partition coefficients at equilibrium. We speculate that the availability of Cr in the melt increased the clinopyroxene Na partition coefficient via a coupled substitution thereby enhancing this phase with the kosmochlor component. The high temperature minerals, fine-grain sizes, bulk compositions and common occurrence in the SD tracks and IDPs support the idea that Kool grains could have been precursors to type II chondrules in ordinary chondrites. These grains, however, have not been observed in these meteorites suggesting that they were destroyed during chondrule formation and recycling or were not present in the nebula at the time and location where meteoritic chondrules formed.
Quantum effects on conformational equilibria

Some relatively preliminary investigations are made into the nature of quantum effects on conformational equilibria with the aid of simple gas phase models and a semiclassical method. The case of ethane is first used to test the semiclassical method and to define the concepts of an effective rotational barrier and an effective zero point energy. Internal rotation in n‐butane and some alkyl radicals is then examined. At liquid nitrogen temperatures, butane is predicted to have its trans/gauche equilibrium constant shifted relative to its classical value by an amount roughly equal to (and in the opposite direction from) the shift induced by a hypothetical hard sphere solvent. In the case of certain alkyl radicals, it is pointed out how the occurrence of quantum effects may actually help resolve the current disagreement between solution ESR experiments and theoretical predictions.
Lupus anticoagulant induces a selective defect in thrombin-mediated endothelial prostacyclin release and platelet aggregation.

Summary A patient with microvascular thrombosis and thrombocytopenia was found to have a high-titre lupus anticoagulant. The biological effects of the patient's lupus anticoagulant were studied using whole patient serum and plasma, Staph Protein A eluate, and affinity-purified lupus anticoagulant. The latter was isolated by immunoadsorption of serum onto cardiolipin/phosphatidylserine/cholesterol liposomes. Each source of lupus anticoagulant demonstrated‘anticoagulant’activity, defined as prolongation of a modified kaolin clotting time, and contained antibody which bound to endothelial monolayers. Each interfered with thrombin-mediated prostacyclin release from endothelial cells, but had no effect on arachidonate-induced prostacyclin release. In addition, the lupus anticoagulant selectively blocked platelet aggregation in response to thrombin, but not in response to arachidonate, ADP or epinephrine. Lupus anticoagulant also reduced thrombin-stimulated shifts in cytosolic calcium. Thrombin-mediated membrane inositol metabolism and total thrombin binding to endothelium were unaffected by lupus anticoagulant, and another endothelial anticoagulant function related thrombin binding, Protein C activation by thrombomodulin, was not altered. We conclude that the binding of lupus anticoagulant to endothelial cells and platelets does not prevent all thrombin signalling events, but does interrupt prostacyclin production.
Phylogenetic comparisons of bacterial communities from serpentine and nonserpentine soils.

I present the results of a culture-independent survey of soil bacterial communities from serpentine soils and adjacent nonserpentine comparator soils using a variety of newly developed phylogenetically based statistical tools. The study design included site-based replication of the serpentine-to-nonserpentine community comparison over a regional scale (∼100 km) in Northern California and Southern Oregon by producing 16S rRNA clone libraries from pairs of samples taken on either side of the serepentine-nonserpentine edaphic boundary at three geographical sites. At the division level, the serpentine and nonserpentine communities were similar to each other and to previous data from forest soils. Comparisons of both richness and Shannon diversity produced no significant differences between any of the libraries, but the vast majority of phylogenetically based tests were significant, even with only 50 sequences per library. These results suggest that most samples were distinct, consisting of a collection of lineages generally not found in other samples. The pattern of results showed that serpentine communities tended to be more similar to each other than they were to nonserpentine communities, and these differences were at a lower taxonomic scale. Comparisons of two nonserpentine communities generally showed differences, and some results suggest that the geographical site may control community composition as well. These results show the power of phylogenetic tests to discern differences between 16S rRNA libraries compared to tests that discard DNA data to bin sequences into operational taxonomic units, and they stress the importance of replication at larger scales for inferences regarding microbial biogeography.
PRELIMINARY OUTCOMES FOLLOWING CRYOSURGICAL ABLATION OF THE PROSTATE IN PATIENTS WITH CLINICALLY LOCALIZED PROSTATE CARCINOMA

AbstractPurpose: Cryosurgical ablation of the prostate is a novel therapeutic modality that induces cell lysis in the prostate by direct application of low temperatures. We have been conducting an ongoing prospective pilot study of the use of cryosurgical prostate ablation in treating patients with nonmetastatic prostate adenocarcinoma since January 1993. Results in 145 consecutive patients with mean 36 months and minimum 12 months of followup are presented.Materials and Methods: Accrual was open to patients with clinical stages T1a to T3c prostate adenocarcinoma. Pelvic lymph node dissections were recommended but not required for patients with prostate specific antigen (PSA) greater than 15 ng./ml. before study entry. PSA changes, random prostate biopsy findings and morbidities after cryosurgical prostate ablation were recorded for each patient.Results: Overall actuarial rates at 42 months for maintaining PSA less than 0.3 and less than 1.0 were 59% and 66%, respectively. The overall actuarial progressio...
Ordered Micelle Structuring in Thin Films Formed from Anionic Surfactant Solutions

Reflected light micro-interferometry was used to observe stratification (i.e., the kinetics of layered structuring) in thinning foam films formed from micellar solutions of sodium n-alkyl sulfates at concentrations much lower than those at which liquid crystalline structures form in bulk solutions. The effects of surfactant concentration and chain length, added electrolyte, and capillary pressure on the step-wise jump transition thicknesses have been investigated. We have further conducted a model study with films formed from aqueous dispersions of latex particles. In similar fashion to those formed from micellar solutions, the thinning films changed thickness with regular step-wise jump transitions, and the films exhibited a number of metastable equilibria. These observations verify that the stratification of thin liquid films can be explained as a layer-by-layer thinning of ordered structures of micelles or colloidal particles formed inside the film. The stratification-nonstratification phase diagram is presented for anionic micelles and is similar to the order-disorder phase diagram for latexes. In the accompanying paper (Part II) we show that the phenomenon of stratification and ordered micellar structures is governed by the long range electrostatic repulsion beteen the ionic micelles and the restricted volume of the film. This present study provides evidence, for the first time, for the presence of structural forces in thin films with thicknesses on the order of 100 nm and strongly suggests that the free liquid film dynamics may be used as a probe to study the ordering in, and stability of, microheterogeneous systems.
Treatment setting and baseline substance use severity interact to predict patients' outcomes.

Aims This study tested the hypothesis that patients with more severe substance use disorders (SUDs) at intake respond better when treated in more structured and intensive settings (i.e. in-patient/residential versus out-patient), whereas patients with less severe SUD problems have similar outcomes regardless of treatment setting. Design, setting and participants Up to 50 new patients were selected randomly from each of a random and representative sample of 50 Department of Veterans Affairs (VA) SUD treatment programs (total n = 1917 patients), and were followed-up an average of 6.7 months later (n = 1277). Measures Patients completed a brief self-report version of the Addiction Severity Index (ASI) at baseline and at follow-up. Findings In mixed-model regression analyses, baseline substance use severity predicted follow-up substance use severity and there were no main effects of treatment setting. However, interaction effects were found, such that more severe patients experienced better alcohol and drug outcomes following in-patient/residential treatment versus out-patient treatment; on the other hand, patients with lower baseline ASI drug severity had better drug outcomes following out-patient treatment than in-patient treatment. Treatment setting was unrelated to alcohol outcomes in patients with less severe ASI alcohol scores. Conclusions Results provide some support to the matching hypothesis that for patients who have higher levels of substance use severity at intake, treatment in in-patient/residential treatment settings is associated with better outcomes than out-patient treatment. More research needs to be conducted before in-patient/residential settings are further reduced as a part of the SUD continuum of care in the United States.
Ceramide kinase is required for a normal eicosanoid response and the subsequent orderly migration of fibroblasts

In these studies, the role of ceramide-1-phosphate (C1P) in the wound-healing process was investigated. Specifically, fibroblasts isolated from mice with the known anabolic enzyme for C1P, ceramide kinase (CERK), ablated (CERK−/− mice) and their wild-type littermates (CERK+/+) were subjected to in vitro wound-healing assays. Simulation of mechanical trauma of a wound by scratching a monolayer of fibroblasts from CERK+/+ mice demonstrated steadily increasing levels of arachidonic acid in a time-dependent manner in stark contrast to CERK−/− fibroblasts. This observed difference was reflected in scratch-induced eicosanoid levels. Similar, but somewhat less intense, changes were observed in a more complex system utilizing skin biopsies obtained from CERK-null mice. Importantly, C1P levels increased during the early stages of human wound healing correlating with the transition from the inflammatory stage to the peak of the fibroplasia stage (e.g., proliferation and migration of fibroblasts). Finally, the loss of proper eicosanoid response translated into an abnormal migration pattern for the fibroblasts isolated from CERK−/−. As the proper migration of fibroblasts is one of the necessary steps of wound healing, these studies demonstrate a novel requirement for the CERK-derived C1P in the proper healing response of wounds.
Fluorescence decay and quantum yield characteristics of acridine orange and proflavine bound to DNA.

Abstract Fluorescence properties (quantum yield, decay curve, lifetime and polarization) of acridine orange and proflavine bound to DNA were examined as a function of nucleotide to dye (P/D) ratio. First, mean fluoiescence lifetimes were determined by the phase-shift measurements. The lifetime and quantum yield of acridine orange increased in a parallel fashion with increasing P/D ratio. There was no parallel relation between the lifetime and quantum yield for proflavine; the lifetime showed a minimum around P/D = 10. Next, fluorescence decay curves were measured by the monophoton counting technique and analyzed with the aid of the method of moments and the Laplace transform method. The results showed that the fluorescence decay of bound acridine orange was exponential above P/D = 10. On the other hand, the decay of bound proflavine was exponential above P/D = 100, but markedly deviated from exponentiality with decreasing P/D ratio. The results of fluorescence polarization suggested that this phenomenon is the result of Forster energy transfer between proflavine molecules bound to the fluorescent site (AT pair) and bound to the quenching site (GC pair). Critical transfer distances were 26-4 and 37.0 A, respectively, for bound proflavine and acridine orange.
Stem cells of ependymoma

Ependymomas are tumours that arise throughout the central nervous system. Little is known regarding the aberrant cellular and molecular processes that generate these tumours. This lack of knowledge has hampered efforts to reduce the significant mortality and morbidity that are associated with ependymoma. Here, we review recent data that suggest that radial glia are cells of origin of ependymoma, and discuss the processes that might transform these neural progenitors into ependymoma cancer stem cells.
The Relationship of Walking Intensity to Total and Cause-Specific Mortality. Results from the National Walkers’ Health Study

Purpose Test whether: 1) walking intensity predicts mortality when adjusted for walking energy expenditure, and 2) slow walking pace (≥24-minute mile) identifies subjects at substantially elevated risk for mortality. Methods Hazard ratios from Cox proportional survival analyses of all-cause and cause-specific mortality vs. usual walking pace (min/mile) in 7,374 male and 31,607 female recreational walkers. Survival times were left censored for age at entry into the study. Other causes of death were treated as a competing risk for the analyses of cause-specific mortality. All analyses were adjusted for sex, education, baseline smoking, prior heart attack, aspirin use, diet, BMI, and walking energy expenditure. Deaths within one year of baseline were excluded. Results The National Death Index identified 1968 deaths during the average 9.4-year mortality surveillance. Each additional minute per mile in walking pace was associated with an increased risk of mortality due to all causes (1.8% increase, P=10-5), cardiovascular diseases (2.4% increase, P=0.001, 637 deaths), ischemic heart disease (2.8% increase, P=0.003, 336 deaths), heart failure (6.5% increase, P=0.001, 36 deaths), hypertensive heart disease (6.2% increase, P=0.01, 31 deaths), diabetes (6.3% increase, P=0.004, 32 deaths), and dementia (6.6% increase, P=0.0004, 44 deaths). Those reporting a pace slower than a 24-minute mile were at increased risk for mortality due to all-causes (44.3% increased risk, P=0.0001), cardiovascular diseases (43.9% increased risk, P=0.03), and dementia (5.0-fold increased risk, P=0.0002) even though they satisfied the current exercise recommendations by walking ≥7.5 metabolic equivalent (MET)-hours per week. Conclusions The risk for mortality: 1) decreases in association with walking intensity, and 2) increases substantially in association for walking pace ≥24 minute mile (equivalent to <400m during a six-minute walk test) even among subjects who exercise regularly.
Monte-Carlo approach for power estimation in sequential circuits

In this paper we present a Monte-Carlo based statistical techniques for estimating power in sequential circuits. Mutually independent samples of power are generated by simulating multiple copies of the circuit. Since the approach is simulation-based, spatiotemporal correlations are automatically accounted for. The algorithm iterates until the user-specified accuracy is achieved. Experimental results on ISCAS89 circuits show that reliable results can be obtained in considerably less time than that required by exhaustive simulation.
Navigating in small‐scale space: The role of landmarks and resource monitoring in understanding saddleback tamarin travel

Recent studies of spatial memory in wild nonhuman primates indicate that foragers may rely on a combination of navigational strategies to locate nearby and distant feeding sites. When traveling in large-scale space, tamarins are reported to encode spatial information in the form of a route-based map. However, little is known concerning how wild tamarins navigate in small-scale space (between feeding sites located at a distance of ≤60 m). Therefore, we collected data on range use, diet, and the angle and distance traveled to visit sequential feeding sites in the same group of habituated Bolivian saddleback tamarins (Saguinus fuscicollis weddelli) in 2009 and 2011. For 7–8 hr a day for 54 observation days, we recorded the location of the study group at 10 min intervals using a GPS unit. We then used GIS software to map and analyze the monkeys' movements and travel paths taken between feeding sites. Our results indicate that in small-scale space the tamarins relied on multiple spatial strategies. In 31% of cases travel was route-based. In the remaining 69% of cases, however, the tamarins appeared to attend to the spatial positions of one or more near-to-site landmarks to relocate feeding sites. In doing so they approached the same feeding site from a mean of 4.5 different directions, frequently utilized different arboreal pathways, and traveled approximately 30% longer than then the straight-line distance. In addition, the monkeys' use of non-direct travel paths allowed them to monitor insect and fruit availability in areas within close proximity of currently used food patches. We conclude that the use of an integrated spatial strategy (route-based travel and attention to near-to-goal landmarks) provides tamarins with the opportunity to relocate productive feeding sites as well as monitor the availability of nearby resources in small-scale space. Am. J. Primatol. Am. J. Primatol. 76:447–459, 2014. © 2013 Wiley Periodicals, Inc.
Greedy transformation of evolutionary algorithm search spaces for scheduling problems

Many scheduling algorithms search the space of possible solutions (schedules), but some instead search the space of permutations of the set of jobs, employing a greedy algorithm to map any such permutation to a schedule that can be evaluated by the fitness function. The search algorithm is thus simplified because knowledge about problem domain details is encapsulated in the greedy algorithm that constructs schedules, and the fitness function that evaluates them. The variety of types of algorithms for which this sort of "greedy transformation" has proven effective, and the range of successful applications, prompts us to look more closely at how such transformations may also make good solutions easier to find. In this paper we experimentally evaluate some characteristics of search spaces under greedy transformations as a first step toward understanding why this technique is effective.
Fatigue Behavior of Carbon Fiber Reinforced Polymer-Strengthened Reinforced Concrete Bridge Girders

This study examines the effects of one-dimensional fiber-reinforced polymer (FRP) composite rehabilitation systems on the flexural fatigue performance of reinforced concrete bridge girders. Eight 508 mm deep and 5.6 m long reinforced concrete T-beams, with and without bonded FRP reinforcement on their tensile surfaces, were tested with a concentrated load at midspan under constant amplitude cyclic loading. The objective of this investigation is to establish the effect that these repair systems have on the fatigue behavior and remaining life of the girders. Results indicate that the fatigue behavior of such retrofit beams is controlled by the fatigue behavior of the reinforcing steel. The fatigue life of a reinforced concrete beam can be increased by the application of an FRP retrofit, which relieves some of the stress carried by the steel. The observed increase in fatigue life, however, is limited by the quality of the bond between the carbon FRP and concrete substrate. Debonding, initiating at midspan and progressing to a support, is common and is driven partially by the crack distribution and shear deformations of the beam.
Demonstrating the ABELS system using real-world scenarios

The explosive growth of the Internet has led to new opportunities for developing and integrating large, data-driven applications such as simulations. The Agent-Based Environment for Linking Simulations (ABELS) framework allows the formation of a dynamic "data and simulation cloud" of independent networked resources. Specifically, ABELS provides run-time matching of data producers and consumers and handles the communication between those resources. This paper presents three scenarios that demonstrate how ABELS can be used with real-world, data-driven applications. Furthermore, it demonstrates the functionality of our system using a hurricane preparedness case study.
Cyber security evaluation of synchrophasors in a power system

The addition of synchrophasors such as phasor measurement units (PMUs) to the existing power grid will enhance real-time monitoring and analysis of the grid. The PMU collects bus voltage, line current, and frequency measurements and uses the communication network to send the measurements to the respective substation(s)/control center(s). Since this approach relies on network infrastructure, possible cyber security vulnerabilities have to be addressed to ensure that is stable, secure, and reliable. In this paper, security vulnerabilities associated with a synchrophasor network in a benchmark IEEE 68 bus (New England/New York) power system model are examined. Currently known feasible attacks are demonstrated. Recommended testing and verification methods are also presented.
Bedload transport of fine gravel observed by motion-picture photography

Motion pictures taken at Duck Creek, a clear stream 6.5 m wide and 35 cm deep near Pinedale, Wyoming, provide detailed, quantitative information on both the modes of motion of individual bedload particles and the collective motions of large numbers of them. Bed shear stress was approximately 6 Pa (60 dynes cm−2), which was about twice the threshold for movement of the 4 mm median diameter fine gravel bed material; and transport was almost entirely as bedload. The displacements of individual particles occurred mainly by rolling of the majority of the particles and saltation of the smallest ones, and rarely by brief sliding of large, angular ones. Entrainment was principally by rollover of the larger particles and liftoff of the smaller ones, and infrequently by ejection caused by impacts, whereas distrainment was primarily by diminution of fluid forces in the case of rolling particles and by collisions with larger bed particles in the case of saltating ones. The displacement times averaged about 0.2−0.4 s and generally were much shorter than the intervening repose times. The collective motions of the particles were characterized by frequent, brief, localized, random sweep-transport events of very high rates of entrainment and transport, which in the aggregate transported approximately 70% of the total load moved. These events occurred 9% of the time at any particular point of the bed, lasted 1–2 s, affected areas typically 20–50 cm long by 10–20 cm wide, and involved bedload concentrations approximately 10 times greater than background. The distances travelled during displacements averaged about 15 times the particle diameter. Despite the differences in their dominant modes of movement, the 8–16 mm particles typically travelled only about 30% slower during displacement than the 2–4 mm ones, whose speeds averaged 21 cm s−1. Particles starting from the same point not only moved intermittently downstream but also dispersed both longitudinally and transversely, with diffusivities of 4.6 and 0.26 cm2 s−1, respectively. The bedload transport rates measured from the films were consistent with those determined conventionally with a bedload sampler. The 2–4 mm particles were entrained 6 times faster on finer areas of the bed, where 8–16 mm particles covered 6% of the surface area, than on coarser ones, where they covered 12%, even though 2–4 and 4–8 mm particles covered practically the same percentage areas in both cases. The 4–8 and 8–16 mm particles, in contrast, were entrained at the same rates in both cases. To within the statistical uncertainty, the rates of distrainment balanced the rates of entrainment for all three sizes, and were approximately proportional to the corresponding concentrations of bedload.
Temporal variation in selection on body length and date of return in a wild population of coho salmon, Oncorhynchus kisutch

Background A number of studies have measured selection in nature to understand how populations adapt to their environment; however, the temporal dynamics of selection are rarely investigated. The aim of this study was to assess the temporal variation in selection by comparing the mode, direction and strength of selection on fitness-related traits between two cohorts of coho salmon (Oncorhynchus kisutch). Specifically, we quantified individual reproductive success and examined selection on date of return and body length in a wild population at Big Beef Creek, Washington (USA).
“So Full of Myself as a Chick” Goth Women, Sexual Independence, and Gender Egalitarianism

Drawing on interviews, participant observation, and Internet postings, this article analyzes gender in a local Goth scene. These Goths use the confines of the subcultural scene, where they are relatively safe from outsider view, and the scene’s celebration of sexuality as resources to resist mainstream notions of passive femininity. This article probes the struggles of women in this Goth scene to examine the broader possibilities and limitations of strategies of active feminine sexuality in gaining gender egalitarianism. I argue that although these women do transform sexual expectations and experiences, their gains are hampered by an overly narrow vision of gender egalitarianism that both obfuscates the broader landscape of gender inequality and blurs the reproduction of an ideological system in which romance trumps sex.
Phylogenetic analysis and fossil plants

Stein Jr., W.E., 1987. Phylogenetic analysis and fossil plants. Rev. Palaeobot. Palynol., 50:31 61. This paper presents a perspective on the relationship between cladistic methods and the study of fossil plants. Paleobotany has been slow in evaluating the potential of these and other explicit methods compared to other branches of systematics. However, the unique or particularly difficult problems paleobotanists face make more interesting, rather than prohibit, their application. A model of a cladistic approach to phylogenetic analysis is introduced in order to evaluate what role fossils, including fossil plants, should play in phylogenetic analysis. Major elements of the model include sets of hypotheses about useful systematic comparison, phylogenetic relationship, evolutionary pattern and process, and age, linked by recursive directional arguments. Arguments at one level only, those linking characters with the cladogram, are viewed as being strictly deductive. Character hypotheses at the highest level are distinguished by the term '¢cladistic character". When cladistic characters are compatible, estimates of phylogeny suggested by each may be readily combined into a summary result. However, character conflict is common and represents a major challenge to the ultimate success of cladistic methods. The main advantage of cladistic characters lies in the attempt to separate out portions of complex phylogenetic hypotheses for independent scrutiny and debate. Under the model of phylogenetic analysis presented here, it is argued that fossils provide morphological information, not obtainable by other means of inquiry, which may have a profound effect on our view of characters and relationship. Fossils also provide estimates of age useful in two distinct ways. The first involves using age estimates of states, combined with external criteria such as out-group analysis, in providing defensible proximity and polarity proposals for cladistic characters. The second involves using age estimates of entire taxa to judge historical plausibility of a set of phylogenetic hypotheses generated from a cladogram. Incompatible characters may also be analyzed in this way, allowing evaluation of the plausibility of alternative character formulations. The use of fossils in phylogenetic analysis tends to emphasize the necessity of coming to terms explicitly with the ancestor-descendant relationship in cladistic methods. It is proposed that, when properly formulated, the relationship is similar in structure to other phylogenetic hypotheses and at least partly addressed by the hypothetico-deductive format.
Bilingual intonation patterns: Evidence of language change from Turkish-German bilingual children

This article discusses Turkish-German bilingual children's intonation patterns as they relate to processes of contact-induced language change. Bilingual speakers use two distinct rises in both Turkish and German. One rise (L*HH%) resembles a characteristic German rise, while the other (L%H%) resembles a characteristic Turkish rise. The rises pattern pragmatically in ways that are non-normative for both Turkish and German. Although this pattern is not clearly attributable to language interference (either borrowing or shift-induced language change), it is certainly the result of language contact. Fusion is proposed to account for the two-way influence between the two languages.