cssi/SciSciGPT-SciSciNet huggingface dataset:
The hydraulic interpretation of turbidites from their grain sizes and sedimentary structures

Previous attempts to deduce the flow parameters of turbidity currents from their deposited sediments have focused on applications of criteria for the suspension or autosuspension of the grains and on hydrodynamic interpretations of the characteristic Bouma sequence of sedimentary structures. There has been a considerable diversity of opinion, however, as to how the transport criteria relate to the observed deposited grain-size distribution, and no attempt has been made to determine whether the separate analyses of deposited sediments and sedimentary structures agree as to the magnitudes of the evaluated flow parameters. Such analyses are performed on a turbidite from the Capistrano Formation (Miocene-Pliocene) of California. This turbidite is normally graded from medium sand at its base to very fine sand and silt at the top, and has the complete sequence of Bouma structures. Only a small degree of cementation has occurred so that samples from the layer could be disaggregated and grain sizes determined both by sieving and sedimentation balance analyses. It was decided to employ the grain-suspension criterion for the calculation of the flow conditions at the time of deposition, published experiments on the pipe-flow of suspensions having demonstrated that this criterion is one of deposition versus non-deposition of grains according to their settling velocities. The published work relating types of sedimentary structures to the sediment grain size and either the flow power or Shield's dimensionless stress is used to evaluate the flow parameters from the observed Bouma sequence. All methods employed yield estimates of the mean flow velocity and bed stress (force per unit bottom area). The evaluated flow parameters for the transition from a flat bed to ripples (Bouma B to C divisions) are nearly an order of magnitude greater than obtained from the grain-suspension criterion where the calculations are based on the median grain size of the deposited sediments. Agreement results only if the calculations utilizing the suspension criterion are based on nearly the coarsest grains deposited at any instant, a procedure that is difficult to justify with the expected sediment deposition from a waning current. Inclusion of other factors, such as possible lags in sediment deposition or ripple formation beneath the decelerating flow, provide no firm explanation as to the cause of the discrepancy between the results based on the two approaches, and in nearly all cases their inclusion would increase the difference. Something is amiss with our procedures for the hydraulic interpretation of sediments which can be resolved only by further study.
Transmission electron microscopic investigation of a Pd–Ag–In–Sn dental alloy

Abstract With the price volatility of palladium, there has been renewed interest in palladium–silver alloys for metal-ceramic restorations in dentistry. The microstructures of a popular Pd–Ag dental alloy were investigated in the as-cast and simulated porcelain-firing heat-treated conditions, using transmission electron microscopy. In the as-cast condition, the microstructure was strongly influenced by microsegregation, and contained the face-centered cubic Pd solid solution matrix, a eutectic structure with lattice parameters that varied for the two phases, and a face-centered tetragonal (fct) precipitate. After heat treatment, the lattice parameters for the two phases in the eutectic structure were uniform, and discontinuous precipitates with {0 1 1} matrix habit planes and dislocations appeared in the matrix. An unusual nanostructured constituent was found in the fct set of eutectic lamellae in the heat-treated alloys.
AN EVALUATION OF SEXUAL BEHAVIOUR CHANGE USING STATISTICAL AND COGNITIVE MODELS

We evaluate sexual behaviour change among homosexual men enrolled in the cohorts in four AIDS Community Demonstration Projects. Behaviour change is classified following the stages of behaviour change model and described using a Markov model. Predictors of behaviour change are identified and evaluated using logit models for correlated data. Sexual behaviour change within the cohort could be modelled as a first-order Markov process. In addition, predictors suggested by models of health behaviour were correlated with particular patterns of sexual behaviour change. Our evaluation revealed a variety of patterns of sexual behaviour change in the cohorts and suggests multi-faceted interventions for promotion of behaviour change.
Observing, modelling, and validating snow redistribution by wind in a Wyoming upper treeline landscape

Abstract Redistribution of snow by wind is a defining feature of the physical environment in high-elevation upper treeline and alpine landscapes where most precipitation is snow and wind speeds are frequently high. In these landscapes, snow, wind, topography, and vegetation interact to produce a pattern of snow deposition where wind-driven snow is eroded from exposed areas and deposited on the lee sides of hills, trees, rocks, and other obstructions. During winters on Libby Flats, a broad, high-elevation ridge located in southeastern Wyoming, USA, snow is heterogeneously distributed with snow depths ranging from 0.1 to 7 m over a lateral span of a few meters. Snow depth variations are principally controlled by the aerodynamic influence of trees on wind, with the deepest drifts forming on the lee sides of krummholz patches and ribbon forests. While precipitation varied from year to year, spatial patterns of snow scouring, drifting, and snowmelt were nearly identical. This characteristic and chronic pattern alters ecosystem structure (e.g., plant species distributions and soil characteristics) and function (e.g., decomposition, primary production, nutrient cycling, and water balance). To better comprehend and predict how ecosystem structure and function change with respect to snow distribution in treeline ecotones, an understanding of the snow transport process, ablation, and subsequent water distribution is required. Since snow accumulation and melt are difficult to observe spatially, we adapted and validated snow transport and land surface models to simulate the heterogeneous snow distributions produced during three consecutive water years (1998–2000). Comparisons of field measurements with model predictions indicate that the linked models generally mimicked the temporal and spatial characteristics of snow accumulation, redistribution, and ablation on Libby Flats. However, considerable modelled and observed discrepancies were associated with shallow or deep snow depths. Model agreement with observations could be improved with higher temporal resolution meteorological data, better resolved terrain and vegetation data, and model improvements.
Screening blood pressure measurement in children: are we saving lives?

Blood Pressure screening in children and adolescents is currently recommended by several prominent medical organizations, including the American Heart Association, the National High Blood Pressure Education Program, the National Heart, Lung, and Blood Institute, the European Society of Hypertension, and the American Academy of Pediatrics. This practice was recently subject to intense scientific review by the U.S. Preventive Services Task Force. The conclusion of the Task Force was that “current evidence is insufficient to assess the balance of benefits and harms of screening for primary hypertension in asymptomatic children and adolescents.” This commentary provides an alternate interpretation of current evidence for blood pressure screening in children and adolescents and highlights its importance as a part of routine medical care.
Assessment of Structural Steel From the World Trade Center Towers. Part III: Physical Damage Caused by Impact of Aircraft

This paper describes damage characteristics and failure modes of the recovered structural steel components from the World Trade Center (WTC) towers WTC 1 and WTC 2. Knowledge of damage to the steel elements played an important role in the investigation by ascertaining the response of the structural steel of the towers to the impact of the planes and by providing information on exterior column damage for correlations with impact damage modeled in the baseline structural performance and aircraft impact damage analysis. Results focus on the five exterior panel sections in the impact region of WTC 1 and the four core columns from near the impact regions of WTC 1 and WTC 2.
Ion extraction from a plasma

An experimental investigation of the physical processes governing ion extraction from a plasma is presented. The screen hole plasma sheath of a multiaperture ion accelerator system is defined by equipotential plots for a variety of accelerator system geometries and operating conditions. A sheath thickness of at least 15 Debye lengths is shown to be typical. The electron density variation within the sheath satisfies a Maxwell‐Boltzmann density distribution at an effective electron temperature dependent on the discharge plasma primary‐to‐Maxwellian electron density ratio. Plasma ion flow up to and through the sheath is predominately one dimensional and the ions enter the sheath with a modified Bohm velocity. Low values of the screen grid thickness to screen hole diameter ratio give good ion focusing and high extracted ion currents because of the effect of screen webbing on ion focusing.
Dietary zinc requirement of the red drum, Sciaenops ocellatus

A feeding trial was conducted to determine the dietary zinc requirement of juvenile red drum, Sciaenops ocellatus, in brackish (6 ppt) water. Semipurified diets containing graded levels of zinc (5, 10, 20, 30 and 40 mg Zn/kg) were fed to juvenile red drum in triplicate aquaria for 8 weeks. Overt signs of zinc deficiency such as suppressed growth and increased mortality were observed within 3 weeks in fish fed the basal diet containing 5 mg Zn/kg. At the end of 8 weeks, scale- and bone-zinc concentrations of fish fed the various diets were significantly (P < 0.01) affected and increased linearly as dietary zinc increased until plateauing around 20 mg Zn/kg diet and greater. Based on these data, 20–25 mg Zn/kg of dry diet was determined to be the minimum dietary zinc requirement of red drum.
Analytical and experimental comparison of probabilistic and deterministic optimization

The objective of this paper is to evaluate experimentally the gain in reliability that can be achieved In the design of a system by using probabilistic optimization instead of deterministic optimization. The design of a truss structure, equipped with tuned dampers and subject to constraints on the dynamic response amplitudes, is used for the investigation. The locations of the dampers and of tuning masses added to the truss are used as design variables. The properties of the dampers are the main sources of uncertainties. The deterministic and probabilistic optimizations are performed with genetic algorithms. Probabilities of failure are measured in the laboratory by testing multiple realizations of deterministic and probabilistic optimum designs. Predicted and measured values of the reliabilities of the concurrent designs are compared. For a design problem selected to maximize the contrast in reliability between the two optimum designs, the probabilistic optimization provided a large improvement in reliability compared with the deterministic optimum design. This improvement was confirmed by experiments.
Strain-induced perpendicular magnetic anisotropy of 100-oriented Ni-Cu superlattices

The uniaxial perpendicular and magnetocrystalline anisotropies in strained 〈100〉-oriented Ni-Cu superlattices have been determined by in-plane and out-of-plane ferromagnetic resonance and magnetization measurements for varying Ni and Cu thicknesses. X-ray-diffraction patterns of the superlattice structure for these films indicate that the Ni lattice contracts while the Cu lattice dilates along the growth direction. Utilizing the measured strain with known elastic and magnetostriction constants for bulk Ni, the calculated strain-induced magnetoelastic anisotropies due to an inverse magnetostriction are in good quantitative agreement with the experimentally determined uniaxial perpendicular anisotropies.
A radioimmunoassay program for Lotus 1–2–3

Abstract Spreadsheet programs have become very popular as convenient ways of performing mathematical operations, as well as entering and organizing data. This paper describes how Lotus 1–2–3 can be used to calculate the results of a radioimmunoassay, a widely used technique in biomedical laboratories.
The detergent solubility properties of a malarial (Plasmodium knowlesi) variant antigen expressed on the surface of infected erythrocytes

Four detergents have been compared for identification of the Plasmodium knowlesi variant antigen on infected erythrocytes by immunoprecipitation analysis. Erythrocytes infected with late trophozoite and schizont forms of cloned asexual parasites were labeled by lactoperoxidase-catalyzed radioiodination and extracted either with the anionic detergents sodium dodecyl sulfate (SDS) or cholate, the neutral detergent Triton X-100, or the zwitterion 3-[(3-cholamidopropyl)di-methylammonio]-1-propane sulfonate (CHAPS). After addition of Triton X-100 to SDS and cholate extracts, parallel immunoprecipitations of the four extracts were performed using rhesus monkey antisera of defined agglutinability. Identical results were obtained with clone Pkl(A+ ), which has 125I-variant antigens of Mr 210,000 and 190,000, and with clone Pkl(B+)l+, which hasvariant antigens of Mr 200,000–205,000. SDS yielded maximal levels of immunoprecipitated 125I-variant antigens. Variant-specific immunoprecipitation was detected in some experiments with Triton X-100 and cholic acid but with significantly lower recovery than with SDS. CHAPS extraction did not yield the variant antigens on immunoprecipitation. The variant antigens could also be identified in Triton X-100-insoluble material by subsequent extraction with SDS, indicating that failure to recover these proteins in the Triton X-100-soluble fraction is due to failure of this detergent to extract the variant antigens rather than to degradation during extraction. We suggest that the 125I-variant antigens either have a structure that renders them intrinsically insoluble in Triton X-100, cholate, or CHAPS, or that they are associated in some way with host cell membrane components that also resist solubilization by these detergents.
Teratogenicity of structural truncates of cyclophosphamide in mice

Truncates of cyclophosphamide including proposed in vivo metabolic products were administered to pregnant mice on day 11 of gestation. Minimal teratogenic dosages were determined: cytoxyl alcohol, 290 mg/kg; cytoxyl amine, 270 mg/kg; phosphoramide mustard, 154 mg/kg; nornitrogen mustard, 1.6 mg/kg; and 3-amino-l-propanol, 5.7 mg/kg. Maternal toxicity was evident in each case. Malformations varied from agent to agent but no agent paralleled cyclophosphamide (20 mg/kg) teratogenicity. Cyclophosphamide produced more frequent and more severe soft tissue and skeletal malformations without maternal toxicity than did any of the cyclophosphamide truncates tested. Common teratogenic effects of cyclophosphamide, cytoxyl alcohol, and nitrogen mustard were polydactyly, oligodactyly, syndactyly, cleft palate, and some skeletal defects. Cytoxyl amine, phosphoramide mustard, nornitrogen mustard, and 3-amino-l-propanol were less teratogenic. Alkylating activities of these agents were determined by nitrobenzyl pyridine reaction in plasma of mice 2, 4, 8, 16, 32, and 64 minutes after intraperitoneal dosages equimolar to cyclophosphamide (100 mg/ kg). No relation between teratogenicity and alkylating potencies of the various agents was demonstrated.
Gravity Indicators in the Near-Infrared Spectra of Brown Dwarfs

We investigate the sensitivity to temperature and gravity of the strong absorption features in the J- and K-band spectra of substellar objects. We compare the spectra of giants and young M dwarfs (of low gravity) to field M and L dwarfs (of high gravity) and to model spectra from the Lyon group. We find that low-resolution spectra of M4-M9 stars and young brown dwarfs at R ~ 350 and signal-to-noise ratios greater than 70 can determine the spectral type to a precision of ±1 subtype using the H2O and CO bands and can measure the surface gravity to ±0.5 dex using the atomic lines of K I and Na I. This result points toward the development of photometric spectral indices to separate low-mass members from foreground and background objects in young clusters and associations. We also emphasize the complexity of the interpretation of the empirical quantities (e.g., spectral types) in terms of the physical variables (e.g., temperature, opacities) in the cool atmospheres of young brown dwarfs.
Two-layer Exchange in an Estuary Basin, with Special Reference to the Baltic Sea

Abstract Stationary and transient states of a two-layer fjord-type estuary are discussed analytically. The forcing functions are the outer salinity S0, the fresh-water supply qf, and a meteorologically forced barotropic transport qm. Forced nonlinear, time-dependent cases have been studied numerically. Some associated laboratory experiments are described. The main results obtained are as follows: (i) A single steady state exists; this is approached in an exponential-like way. (ii) The total mixing through the interface must vary with depth (decrease for increasing interface depth) to allow a stable steady state. (iii) The static stability increases with increasing fresh-water supply, up to a critical value where the two-layer model breaks down. (iv) An added oscillatory component in S0 increases and in qf decreases the esturay salinity and the static stability. The effect of an oscillatory qm may go in either direction. (v) The statistical steady state is sensitive to certain high-order statistical featur...
Functional 2:1 A-V block within the His-Purkinje system. Simulation of type II second-degree A-V block.

In eight subjects in whom the effective refractory period of the His-Purkinje system was determined to be longer than that of the A-V node or atrium, abrupt acceleration of the atrial rate resulted in either 2:1 block within the His-Purkinje system or 1:1 A-V conduction. The former conduction pattern simulated a type II second-degree A-V block. The occurrence of either 2:1 block within the His-Purkinje system or 1:1 A-V conduction was determined primarily by (1) an effective refractory period of the His-Purkinje system which exceeded that of the A-V node, (2) the coupling interval of the first atrial capture beat and its effect or lack thereof on the refractory period of His-Purkinje system as it relates to changes in ventricular cycle length, and (3) the relative speed of A-V nodal conduction time. The distinction between this functional 2:1 block within the His-Purkinje system and a true type II second-degree block is discussed from both the clinical and electrophysiologic points of view. Functional 2:1 block within the His-Purkinje can also result when sudden acceleration of atrial rate occurs spontaneously such as in atrial flutter or A-V nodal reentrant atrial tachycardias.
Myocarditis and Dilated Cardiomyopathy: Twins or Distant Relatives?

Myocarditis and dilated cardiomyopathy both commonly present as new unexplained heart failure. This similarity raises the question of the interrelation of these disorders. What proportion of dilated c
A technique to evaluate styrofoam cutouts used in irregular field shaping.

Abstract A simple technique to evaluate styrofoam cutouts used in irregular field shaping is described. The technique consists of rendering visible the edges of the cutout on a radiograph. The edges of a styrofoam cutout are made radiopaque by spraying Renografin-76 onto the side walls of the cutout; the cutout then is radiographed with the patient in treatment simulation position. The radiograph shows dearly the outline of the area to be shielded on the patient's anatomy, with a sharp image of the opaque media.
Kinetic studies of the glycerophosphate acyltransferase from Euglena microsomes, including the effects of serum albumin

Abstract The kinetics of the reaction catalyzed by acyl-CoA: sn-glycerol-3-phosphate O-acyltransferase solubilized from Euglena gracilis microsomes were examined. For myristoyl-, palmitoyl-, stearoyl-, and oleoyl-CoAs, the initial reaction rates rose with increasing substrate concentration up to an optimal concentration that varied from 18.5 to 25 μ M, well above the respective critical micelle concentrations. At higher substrate concentrations, reaction was progressively inhibited. Arachidoyl-CoA was a relatively poor substrate for the acyltransferase, and substrate inhibition was not seen with it. Km values for acyl-CoAs ranged from 13 to 20 μ M while the corresponding V values varied almost 40-fold. Bovine serum albumin, among other effects, caused a change in the kinetic pattern of the reaction acyl-CoA dependency. Both acyl-CoA micelles and albumin-bound acyl-CoA were substrates. The binding of palmitoyl- and oleoyl-CoA was 2.7 and 1.5 mol, respectively, per mol of albumin. The critical micelle concentration of palmitoyl-CoA under the reaction conditions was shown by low angle light scattering photometry to be 7.1 p.M. The sn-glycerol 3-phosphate concentration dependency of the acyltransferase initial velocity exhibited Michaelis-Menten kinetics with Km values of 1.3 and 2.9 mM in the presence of 12.5 and 25 μM palmitoyl-CoA, respectively. The substrate analogues sn-glyceraldehyde 3-phosphate and dihydroxyacetone phosphate inhibited the reaction.
Length-minimization design considerations in photonic integrated circuits incorporating directional couplers

Because directional couplers involve channel waveguides which are very close to one another, transition regions to regions where channel waveguides are widely separated are utilized. The total length of a directional coupler and transition regions can be minimized for a particular degree of field confinement. Calculations presented for LiNbO3-, GaAlAs-, and SiO2/Si-based optical channel waveguides demonstrate the presence of a minimum total length corresponding to a particular degree of field confinement. The overall length at the minimum is shown to be significantly lower than for other values of field confinement allowing single-mode operation. This implies that either more devices can be integrated on a substrate or that less material is needed for an integrated optical circuit.
Loss of function polymorphisms in NAT1 protect against spina bifida

Periconceptional folic acid supplementation reduces the risk of having a child with spina bifida. N-acetyltransferase 1 (NAT1) participates in the catabolism of folates and the acetylation of aromatic and heterocyclic amines. Hence, functional polymorphisms in NAT1, the gene encoding NAT1, could influence the risk of spina bifida via either folate catabolism or acetylation of exogenous agents. Individuals with spina bifida and their parents were genotyped for six NAT1 single nucleotide polymorphisms (SNPs) for which the less common allele is associated with reduced or absent enzyme activity (i.e. 97C>T, 190C>T, 559C>T/560G>A, 640T>G and 752A>T). In addition, a “composite” NAT1 genotype was defined as a function of the genotyped SNPs. Descriptive analyses of the SNPs and of the composite genotype indicated that heterozygous parents were more likely to transmit the common allele than the rare allele to their affected offspring. Furthermore, matings of mothers homozygous for the common allele and heterozygous fathers were more common than the reciprocal matings. Log-linear analyses confirmed that both the maternal (P = 0.008) and offspring (P = 0.003) composite NAT1 genotypes were significantly related to the risk of spina bifida. NAT1 variants that reduce or abolish enzyme activity appear to protect against spina bifida, and to exert their influence via both the maternal and the offspring genotypes. These associations may be attributable to a decrease in either folate catabolism or the conversion of exogenous agents to teratogenic derivatives in women and/or developing embryos with a NAT1 genotype that includes a loss of function allele relative to those who do not.
ADCP measurements of the distribution and abundance of euphausiids near the Antarctic Peninsula in winter

Euphausiid populations were observed in Gerlache Strait, Antarctic Peninsula region, during austral winter 1992 (12 July–14 Aug) using a hull-mounted 153-kHz acoustic Doppler current profiler and a multiple opening and closing net and environmental sensing system (MOCNESS). Theoretical estimates of target strength based on a straight cylinder model and applied to the numbers and sizes of euphausiids in net samples yielded estimates of mean volume backscattering strength (MVBS) that compared favorably with observed values at low abundances. However, net samples underestimated biomass by almost two orders of magnitude at high abundances, a feature we attribute to net avoidance. Other taxonomic groups of macrozooplankton did not appear to contribute significantly to acoustic backscatter. Distributions of euphausiids were similar to those observed in summer; we found no evidence for abundant aggregations immediately below surface sea-ice. Euphausia superba dominated the biomass at all stations; individuals of approximately 22 mm were most abundant at 30–70 m depth, whereas 40-mm individuals were most abundant at 90–130 m. Thysanoessa macrura was positioned deeper in the water column, from 150 to 250 m, and Euphausia crystallorophias was centered on 100 m. The first two species were distributed throughout the study area, but E. crystallorophias was concentrated in coastal embayments. Total wet weight biomass ranged from 0.0009 to 9 g m−3, dry weight ranged from 0.002 to 18 g m−3, and protein ranged from 0.0009 to 9 g m−3, mostly concentrated in the 30–70 m depth stratum. Over the upper 200 m of the water column integrated wet weight biomass estimated from ADCP data was in the range from 29 g m−2 to 92 kg m−2.
Magnetic gap excitations in a one-dimensional mixed spin antiferromagnet Nd 2 BaNiO 5

Magnetic excitations in a ${\mathrm{Nd}}_{2}$${\mathrm{BaNiO}}_{5}$ powder sample were investigated by inelastic neutron scattering. Well-defined one-dimensional (1D) gap modes were observed above and below the N\'eel temperature ${\mathit{T}}_{\mathit{N}}$=24 K. In both temperature regimes the measured dynamic structure factor was found to be consistent with that calculated for transverse Haldane gap modes in a quantum-disordered S=1 linear-chain antiferromagnet. The energy gap does not show any appreciable T dependence at T\ensuremath{\gtrsim}${\mathit{T}}_{\mathit{N}}$. However, in the ordered phase the spin gap increases. The observed behavior is totally different from that found in other Haldane gap systems undergoing 3D antiferromagnetic ordering, such as ${\mathrm{CsNiCl}}_{3}$. \textcopyright{} 1996 The American Physical Society.
Automated design and analysis system for design of custom orthopedic implants

A parametric model for implant design has been developed and incorporated into an expert system for prosthesis design and manufacturing. The expert system acquires data concerning the physical characteristics of a patient. The system conceptualizes a space-filling custom design based upon the available data and calculations. The system considers existing off-the-shelf designs and the custom design as parallel alternatives and applies geometric criteria to eliminate designs that are incompatible with the patient's data. The remaining designs are used to generate finite element models, and are evaluated for bone/prosthesis stress levels. The system “reasons” about the final designs in an iterative fashion. The expert system was used to evaluate possible prosthesis designs for a “typical” patient. Out of six off-the-shelf designs, three were rejected on the basis of incompatible geometries. The custom design was the closest fit as far as space-filling property is considered. All the designs were analyzed for excessive stress levels but none were found to have stresses above the critical stresses.
Prediction of Wormhole Population Density in Carbonate Matrix Acidizing

The efficiency of a carbonate matrix acidizing treatment relies strongly on the dominant wormhole channels formed during the treatment. We have developed and confirmed a theory to predict when the dominant wormhole channels are most efficiently created. Based on this theory, a wormhole population density model was developed In a carbonate acidizing treatment design, the acid volume needed to bypass the near wellbore damage area or penetrate a distance away from the wellbore depends not only on wormhole propagation distance but also on how many wormholes are created. This study investigates the wormhole population density, which means how many wormholes per area of rock surface or per wellbore length will be created. The study is based on the following strategy. For a given rock/acid system, the optimal acid injection flux at which dominant wormholes are initiated is obtained from the wormhole propagation theory. For a given formation, a corresponding pressure gradient at the optimal acid flux is calculated. This pressure gradient is also called the wormhole initiation pressure gradient. When a wormhole is initiated at an arbitrary point along the wellbore, the local pressure distribution is disturbed, resulting in lower pressure gradients into the formation in the region surrounding the wormholes. In this region of reduced pressure gradient and hence, reduced flux, initiation of other wormholes is suppressed. At a sufficient distance from the initial wormhole, the pressure field is undisturbed and other wormholes will develop. We numerically simulated the flow field around a wellbore with a wormhole extending into the formation to quantify this phenomenon. From this study, we predict the wormhole population density along a wellbore as a function of the acidizing conditions. An example is provided to show the application of the wormhole population density model in a treatment design. Fluid loss through the walls of the wormholes and wellbore, optimal acid injection flux, and wormhole propagation rate are also taken into account in this example. The example shows how the wormhole population density model is used to predict the required acid volume (gal/ft) to yield the desired productivity improvement.
Measuring management success: Experience with United States fisheries

Abstract Many articles have been published in recent years criticizing the management of living marine resources based solely on biological stock conservation criteria. In the United States and in many parts of the rest of the world, multiple management objectives and goals in addition to stock conservation must be met by fishery managers responsible for the marine resources under their control. An alternative management metric, conservation efficiency, is recommended based instead on a multi-disciplinary scientific framework that captures these different goals and the behavior of participants in the fishery. On the basis of the constraints facing managers, resources can be conserved and the quality of life of consumptive and nonconsumptive fishery participants improved.
Reactions of H3O+(H2O)0.1 with alkylbenzenes from 298 to 1200 K

Rate constants and branching fractions have been measured for the reactions of H3O+ and H3O+(H2O) with toluene (C7H8), ethylbenzene (C8H10), and n-propylbenzene (C9H12) as a function of temperature using a variable temperature-selected ion flow tube (VT-SIFT) and a high-temperature flowing afterglow (HTFA). The reactions have been studied up to 1200, 1000, and 900 K for toluene, ethylbenzene, and n-propylbenzene, respectively. The measurements are the first for H3O+(H2O) with these reactants. The H3O+ + alkylbenzene reaction rate constants are equal to the collision rate constants given by the Su−Chesnavich equation at all temperatures. Both nondissociative and dissociative proton-transfer products are observed. H3O+ reacts with toluene above 900 K to produce C7H9+, C7H7+, and C6H5+ predominately, whereas only C7H9+ is observed at lower temperatures. Proton transfer from H3O+ to ethylbenzene produces C8H11+ exclusively at 300 K, and by 800 K, C6H7+ is the major product with only minor amounts of C8H11+ an...
Impact of mount St. Helens' emissions on two lichen species of South-Central Washington

Abstract Lichen specimens of Lobaria oregana (Tuck.) Mull. Arg. and Peltigera aphthosa (L.) Wild. collected in October 1980, March 1981 and June 1981 from forested sites within 75 km to the East North-East of Mount St. Helens exhibited significant reductions in internal potassium, phosphorus and gross photosynthetic capability in relation to control areas. In contrast, the same specimens had elevated, internal levels of aluminum and silicon, the two principal elements found in Mount St. Helens' ash. No trends among sites were found for sulfur. Preliminary fumigations with sulfur dioxide, one of several potentially phytotoxic components of St. Helens' emissions, documented significant reduction in these species' photosynthetic capability, a phenomenon correlated with delayed potassium release and initial (but temporary) sulfur accumulation.
Workspace awareness in application development

Coordination of development activities is often the most crucial success factor in a software development team. Typically, teams rely on configuration management (CM) systems for coordination purposes. CM systems manage concurrent development by isolating workspaces. As a result of this isolation, developers are aware of concurrent changes only when they interact with the repository and when changes have already been completed. Breaking this isolation would enable developers to detect potential conflicts as they occur in the workspaces and proactively take steps to avoid them. Our Eclipse plug-in, Palant'r, supports such a workstyle by showing which artifacts have been changed by which developers and by how much.
Electrostatic Precipitation Atomic Absorption Spectrometry

The theory and principles, design, construction, and preliminary evaluation of a system based on the electrostatic precipitation of metals in aerosols on a tungsten collecting electrode, followed by injection of this rod into an electrothermal atomizer for atomic absorption spectrometric determination of the metal, is described. With the use of a manganese aerosol generated by an electrothermal vaporizer, the highest atomic absorption signals—and therefore the optimum charging and collecting efficiency for the geometry of the system as described—were achieved with a negative corona of 15 kV and low aerosol velocity. The system determined copper in the laboratory atmosphere on a near-real-time basis.
Miniature fiber-optic force sensor based on low-coherence Fabry-pérot interferometry for vitreoretinal microsurgery

During vitreoretinal surgery, the surgeon manipulates retinal tissue with tool-to-tissue interaction forces below the human sensory threshold. A force sensor (FS) integrated with conventional surgical tools may significantly improve the surgery outcome by providing tactile feedback to the surgeon. We designed and built a surgical tool integrated with a miniature FS with an outer diameter smaller than 1 mm for vitreoretinal surgery based on low-coherence Fabry–Perot (FP) interferometry. The force sensing elements are located at the tool tip which is in direct contact with tissue during surgery and the FP cavity length is interrogated by a fiber-optic common-path phase-sensitive optical coherence tomography (OCT) system. We have calibrated the FS's response to axial and lateral forces and conducted experiments to verify that our FS can simultaneously measure both axial and lateral force components.
The Piezoelectric and Piezomagnetic Effects on the Surface Wave Speed

the piezoelectric and piezomagnetic effects and the influence of short and open circuit on the surface wave speed are investigated in this paper. First, the elastic, piezoelectric and piezomagnetic coefficients in the considered ordinate system are obtained by Bonde transformation from that in the crystal axes ordinate system. Then, the equation which surface wave speed satisfies is derived from the free traction condition on the surface of piezoelectric and piezomagnetic half space with consideration of short and open circuit case. Some numerical examples are given and the piezoelectric and piezomagnetic effects and the influence of short and open circuit on the surface wave speed are shown graphically.
Dislocation Substructures in Shock-Loaded N1 3 AI

The deformation substructure and mechanical response of the LI 2 intermetallic, Ni 3 Al, subjected to shock-wave loading was studied. Following shock prestrains to shock pressures of approximately 14.0 GPa, 23.5 GPa, and 47.2 GPa, the reload yield strength of Ni 3 Al was measured to be 750 MPa, 1250 MPa and 1500 MPa, respectively. The effective hardening in the shock-loaded Ni 3 Al exceeds that quasistatically obtained when deformed to roughly the same equivalent strains. Coarse planar slip on {111} type planes, a high density of stacking faults, and deformation twins with a {111} type twinning plane were observed in the shocked material. An increasing propensity for twinning and stacking fault formation was observed with higher shock peak pressures.
Obesity drug pipeline not so fat.

Why aren9t there more antiobesity drugs? For one, such drugs must tamper with the biochemistry of metabolism; it9s an essential system for survival and thus sometimes fatal to disrupt. In addition, appetite circuits in the brain use neurotransmitters and receptors that control other body processes. And yet research is beginning to yield important insights into the body9s cast of caloric characters (see p. 846).
Preliminary X-ray crystallographic analysis of canine parvovirus crystals

Abstract The first diffraction pattern of a crystalline single-stranded DNA virus has been obtained. Canine parvovirus was crystallized in a monoclinic P21 unit cell with a = 264.4 A , b = 350.3 A , c = 267.8 A and β = 90.86° (1 A = 0.1 nm). The diffraction pattern extends to at least 2.8 A resolution. Packing of the particles suggests that they have a diameter of around 257 A, in excellent agreement with the reported molecular weight of 5.5 × 106.
Synthesis and characterization of perfluoroaryl-substituted siloles and thiophenes : A series of electron-deficient blue light emitting materials

Perfluoroaryl (Arf)-derivatized siloles and thiophenes have been synthesized via nucleophilic aromatic substitutions (SNAr) involving reactions of hexafluorobenzene, octafluoronaphthalene, and decafluorobiphenyl with the appropriate dilithiosilole or dilithiothiophene intermediate. These compounds are of interest as electron-transport layers and/or blue light emitters, as they possess relatively low LUMO energy levels while maintaining high HOMO−LUMO gaps. Siloles and thiophene were modified in the 2- and 5-positions, while bithiophene substitution occurred in the 5- and 5‘-positions. The HOMO−LUMO gaps, as determined by UV−vis spectroscopy, range between 2.79 and 3.56 eV, while photoluminescence emission spectra reveal λmax,ems values from 396 to 506 nm (corresponding to violet to blue/green emission). Dilute solution-state quantum yields varied from 0.01 to 0.10 for the silole compounds and from 0.25 to 0.71 for the thiophene-based compounds. The experimentally determined LUMO levels (ca. −2.6 to −2.9 e...
A Device for Comparing Callus Growth Rates in Vitro

A device to compare the kinetics of callus growth in vitro is described. Changes in volumes of callus grown in scintillation vials were monitored photometrically without removing the sample from the solid support and medium. It is shown that a fiberglass-paper solid support is superior to a plastic foam solid support for the growth of American chestnut callus.
Estrogen Promotes Breast Cancer Cell Survival in an Inhibitor of Apoptosis (IAP)-Dependent Manner

The estrogen receptor (ER) is a major prognostic and therapeutic marker that is expressed in nearly 75% of breast tumors. We have previously shown that the presence of inflammatory mediators can alter the genomic function of the estrogen receptor (ER) in a gene specific manner. In particular, 17β-estradiol (E2) works in combination with the pro-inflammatory cytokines to enhance the expression of a number of pro-survival factors, including the Inhibitor of Apoptosis (IAP) family member, cIAP2. Here we confirm that mRNA and protein levels for cIAP2, but not the related family members cIAP1 and XIAP, are highly up-regulated in MCF-7 breast cancer cells by E2 and cytokines. Similar regulation of cIAP2 is evident in other ER positive but not ER negative cell lines. In agreement with its role as a pro-survival factor, cIAP2 is highly expressed in a subset of invasive breast carcinomas but not in normal breast tissue or ductal carcinoma in situ. Antagonizing IAPs with mimetics of SMAC, which is a known endogenous IAP antagonist, or knockdown of IAPs by siRNA led to greater cell death by TNFα and prevented E2 from promoting cell survival. In addition, a SMAC mimetic reversed TNFα resistance in ER positive breast cancer cells that express high levels of endogenous IAPs. In summary, our findings indicate a new mechanism by which E2 allows breast cancer cells to evade cell death and suggest that an antagonist of IAPs may be a potential therapeutic option for a subset of ER positive breast tumors.
Adaptive Disturbance Rejection for Flow in a Duct with Time-Varying Upstream Velocity

In this paper we demonstrate adaptive flow control for an incompressible viscous fluid through a two-dimensional channel without using an analytical model. An adaptive disturbance rejection algorithm is implemented within a CFD simulation to reduce the effects of an unknown time-varying inlet velocity disturbance on the performance variable, which is the longitudinal velocity component of the flow at a downstream location. The algorithm requires minimal knowledge of the system, specifically, the numerator coefficients of the transfer functions from the control inputs to the performance variable. System identification, based on CFD simulation prior to disturbance rejection, is used to identify the required parameters.
Mesenchymal Stem Cells Use Integrin β1 Not CXC Chemokine Receptor 4 for Myocardial Migration and Engraftment

Recent evidence has demonstrated the importance of bone marrow-derived mesenchymal stem cells (BM-MSCs) in the repair of damaged myocardium. The molecular mechanisms of engraftment and migration of BM-MSCs in the ischemic myocardium are unknown. In this study, we developed a functional genomics approach toward the identification of mediators of engraftment and migration of BM-MSCs within the ischemic myocardium. Our strategy involves microarray profiling (>22,000 probes) of ischemic hearts, complemented by reverse transcription-polymerase chain reaction and fluorescence-activated cell sorting of corresponding adhesion molecule and cytokine receptors in BM-MSCs to focus on the coexpressed pairs only. Our data revealed nine complementary adhesion molecules and cytokine receptors, including integrin β1, integrin α4, and CXC chemokine receptor 4 (CXCR4). To examine their functional contributions, we first blocked selectively these receptors by preincubation of BM-MSCs with specific neutralizing antibodies, and then we administered these cells intramyocardially. A significant reduction in the total number of BM-MSC in the infarcted myocardium was observed after integrin β1 blockade but not integrin α4 or CXCR4 blockade. The latter observation is distinctively different from that reported for hematopoietic stem cells (HSCs). Thus, our data show that BM-MSCs use a different pathway from HSCs for intramyocardial trafficking and engraftment.
Active oxygen transforms murine myeloid progenitor cells in vitro

Active oxygen (AO) is ubiquitous in nature and its many forms can act as natural carcinogens. Their effect on the transformation of a mouse myeloid progenitor cell line was studied using anchorage-independent colony formation in methylcellulose as the primary assay. Both cytotoxic and non-toxic concentrations of t-butylhydroperoxide, hydrogen peroxide and menadione were examined. At non-cytotoxic concentrations, no AO transformation of these cells from interleukin-3 dependence to factor independence (FI) was observed, even after as many as 25 treatments. At cytotoxic concentrations, however, all 3 classes of AO transformed the cells to FI growth. The most potent agent was t-butyl hydroperoxide (43-fold induction), followed by hydrogen peroxide and then menadione. As little as one exposure to cytotoxic levels of these oxidants induced significant transformation, with relative potencies the same as those observed for multiple exposures. These inductions were not due to general cytotoxic effects, since sodium fluoride and heat-shock treatment gave minimal inductions. AO-induced colonies in methylcellulose that were removed, examined and then injected into pre-irradiated mice uniformly produced tumors. Control, non-treated cells did not form tumors. Tumorigenic cells did not form colonies in methylcellulose at lower plating densities. Furthermore, low numbers of transformed cells supplemented to high density with normal cells showed a small but insufficient increase in colony number as compared with high-density cultures of transformed cells. Our results suggest that the transformants depend upon a paracrine mechanism of growth that is mediated by the transformed cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Online microdialysis-dynamic nanoelectrospray ionization-mass spectrometry for monitoring neuropeptide secretion

Although mass spectrometric approaches offer a sensitive method for identifying cell–cell signaling peptides, the high salt-containing environment of extracellular solutions often complicates characterization of these microscale samples. Accordingly, we have developed a miniature hollow-fiber microdialysis device optimized for desalting small-volume neuronal samples online, with the device directly connected to a modified dynamic nanoelectrospray ionization assembly interfaced with an ion trap mass spectrometer. Improvements over existing designs include placement of a capillary insert within the microdialysis fiber to minimize volume, as well as the use of a microinjector that enables 1 µl sample injections. We present detailed evaluation of peptide recoveries within the microdialysis fiber by liquid chromatography–electrospray ionization–ion trap–mass spectrometry analysis of tissue homogenate in artificial seawater with and without microdialysis. Analyte recoveries after microdialysis ranged from 6 to 78% with higher recoveries of more hydrophilic peptides, while little correlation between mass and percentage recovery was observed in the range studied (2000 to 6000 Da). Recoveries of peptides were the lowest for the analytes with the highest initial mass spectrometry signal intensity. Finally, we illustrate the utility of this microdialysis device for desalting neuropeptides secreted from preparations of the peptidergic bag cell neurons of the marine mollusk, Aplysia californica. Without microdialysis, the high concentration of salts (∼0.5 M) prevented detection of peptides, whereas following online microdialysis–dynamic nanoelectrospray mass spectrometry of stimulated releasate, three peptides (acidic peptide, acidic peptide 1-24 and δ-bag cell peptide) were detected. Copyright © 2005 John Wiley & Sons, Ltd.