cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of pressure on oxidation rate of millimetre-sized char particles

Abstract Mass losses and burnout times of large (0.1, 0.2 g) char particles at pressures of 101–760 kPa were measured in a newly designed high-pressure reactor. A cantilever balance measured instantaneous particle mass and an optical pyrometer measured particle temperature continuously. The process was also videotaped. Sixty-two combustion experiments were conducted with a bituminous coal and a lignite. The reactor air temperature was ∼ 900 or 1200 K and the air flow Reynolds number was varied by a factor of two. Coal particles were placed in a platinum-wire basket inside the reactor at the end of the balance beam. An ash layer accumulated around the particles and receded as the char was consumed. In all tests a linear decrease in cube root of char mass with time was observed during oxidation until near the end of burnout. Changes in air velocity had little effect on oxidation time; increasing gas temperature or increasing pressure from 101 to 507 kPa reduced oxidation times by about one-quarter. Further increase in pressure caused no further reduction in burnout time. Pairs of nearly equally sized particles of coal had oxidation times similar to those of single particles with the same total mass.
A novel apparatus for flame spread study

Abstract One of the challenges in the experimental study of flame spread is that, even if the flame spreads at a steady rate, the propagating flame creates an unsteady phenomenon with respect to the laboratory frame of reference. As a result, only a few studies have been done where the detailed flame structure has been experimentally measured along with the spread rates. In this work, we demonstrate the feasibility of a new flame spread apparatus that moves the fuel in the opposite direction of the flame so as to keep the leading edge of the flame stationary with respect to the laboratory. A thermocouple, fixed to the laboratory frame of reference, in front of the leading edge of the flame, senses the presence of the flame and a PID controller keeps the set point temperature constant by moving the sample holder, driven by a stepper motor, in the opposite direction at the velocity of the spread. Unlike conventional studies, this apparatus, called the flame stabilizer, produces real time spread rate with a time resolution of 0.3 s. In this paper, instantaneous flame spread rate and the visible flame structure are compared between a downward spreading flame and the corresponding stabilized flame for spread over ashless filter paper. The results indicate that the difference between the two configurations are within experimental uncertainties and the stabilized flame can represent a spreading flame adequately, including variability of flame spread rate and the flame geometry, for further observations.
Images of corporate executives in recent fiction

While post-World War II business fiction writers viewed the modern corporation as a threat to individualism, the author makes the point that modern fiction writers do not share that concern. However, modern fiction does describe the business world as being heavily populated by amoral or immoral valueless people, especially among those businessmen engrossed in financial manipulations. The author also observes that the world of business fiction remains an essentially white male dominated one.
Investigation of the reversibility of deformation in silicon sheets

We have investigated the degree to which plastic deformation is reversible in silicon by bending and re-flattening initially defect-free single-crystal Czochralski silicon samples using four-point bending to simulate the deformation experienced during ribbon crystal growth. Optical and scanning electron microscopy of etched sample cross-sections after single bending and bending and re-flattening at 1100° C and 1200° C revealed that the dislocation densities in the re-flattened samples were lower than in singly-bent samples by 60–90%, indicating that dislocations are either being annihilated within the silicon bulk or are exiting the silicon at the free surfaces. There was little evidence of dislocation interaction in the singly-bent single-crystal samples investigated with transmission electron microscopy, so the latter mechanism is more likely. Although the re-flattened specimens have a lower dislocation density, there is little improvement in the minority-carrier diffusion length, measured by electron-beam induced current, which in all cases ranged from 10–20 μm. Since the minority-carrier diffusion length changed little, even with a change in dislocation density from 106 dislocations/cm2–108 dislocations/cm2, other defects must be controlling the diffusion length. There is some correlation between dislocation density and minority-carrier diffusion length within a given sample, but this may be due to indirect effects such as generation of point defects by moving dislocations.
ELECTROMAGNETIC WAVE PROPAGATION ALONG HORIZONTAL WIRE SYSTEMS IN OR NEAR A LAYERED EARTH

ABSTRACT A review of the theory of electromagnetic wave propagation along a system of horizontal wires in a layered medium is given. Numerical results for the propagation constants of a variety of specific structures are presented and examined as functions of wire and medium parameters. The full modal description of such structures is discussed, and its relation to excitation by specific sources is examined. Finally, a brief assessment of currently outstanding problems in this area is given.
Temperature-frequency dependence of dynamic properties of damping materials

Some of the simpler and more reliable techniques for measuring the complex modulus properties of elastomeric and other materials, as functions of frequency, temperature and strain, are reviewed. Use is made of the well established “temperature-frequency superposition” principle to reduce the data to a standardized form useful for engineering purposes. Specific examples of the techniques for reducing the data are discussed. Possible future application of the results to automated data processing and reduction is briefly discussed.
A Site-Specific MIMO Channel Simulator for Hilly and Mountainous Environments

This paper presents a real-time site-specific MIMO channel simulator for communication links in rural environments. This simulator first predicts the delay, angle of arrival and departure, and amplitude of the individual multipath arrivals (direct, ground reflected, terrain diffracted, and terrain scattered) for a specified multiple antenna receiver and transmitter link. The predicted multipath characteristics are then used to compute the tapped delay line coefficients and/or frequency responses of the channel between each transmitter antenna and receiver antenna pair, which are the outputs of the simulator. To demonstrate the use of this simulator, Monte Carlo simulations of SISO and MIMO channel capacity for many databases are performed. Conclusions are drawn on the relationship between capacity, terrain roughness and other channel characteristics.
Direct control of a large conductance K(+)-selective channel by G-proteins in adrenal chromaffin granule membranes.

We report here the presence of a Ca2+-independent K+-channel of large conductance in adrenal chromaffin cell secretory vesicle membranes which is controlled by inhibitory as well as stimulatory heterotrimeric GTP-binding proteins. Using antibodies against specific α subunits for immunoblot analysis, we were able to identify the presence of the inhibitory Gi2 and Gi3 subtypes, as well as the stimulatory G0 and Gs subtypes, but not Gi1 in adrenal chromaffin granules. Furthermore, functional analysis of the K+-channel incorporated into planar lipid bilayers showed that GDPβS and GTPγS have opposite effects on channel activity inducing interconversions between a low and a high open-probability state. Consistent with these findings, the same antibodies antagonized the effects of the nonhydrolyzable analogues on the open probability of the K+-channel.
Intrinsic photon entropy? The darkside of light

Abstract The second law, the Planck equation, and the Gibbs–Duhem relation are used to deduce intrinsic thermodynamic properties of individual photons. It is found that intrinsic photon entropy is independent of the photon wavelength. The intrinsic entropy flux associated with individual photons supplements the entropy flux obtained from standard statistical mechanics. Implications of intrinsic photon entropy for isolated photon systems, a fundamental Planck temperature, and the net photon production of the earth are discussed.
Kinetics of phase transformations in amorphous materials by DSC. Part I

Abstract New analytical methods are introduced for the determination of kinetic parameters of crystallization of an amorphous alloy from DSC transformation exotherms. Isothermal and heating rate methods, as well as a method for separation of two superimposed crystallization reactions are discussed. The basic operating principles and accuracy of the two currently most popular DSC instruments (the DuPont 1090 (E.I. Dupont de Nemours Inc., Wilmington, DE, U.S.A.) and the Perkin Elmer DSC7 (Perkm Elmer Corporation, Norwalk, CT, U.S.A.)) in the context of glass crystallization kinetics are critically evaluated and compared.
Evaluation of household latrine coverage in Kewot woreda, Ethiopia, 3 years after implementing interventions to control blinding trachoma

Abstract The SAFE strategy for trachoma control includes Surgery, Antibiotic distribution, Facial cleanliness and Environmental improvements, including promotion of latrine construction. In this study, household latrine coverage was estimated in order to evaluate SAFE implementation in a district of Ethiopia where reported coverage in rural areas was 97%. Characteristics of latrine adopters and non-adopters were explored. Interviews were conducted in 442 households selected at random in a multistage cluster sample. Overall, estimated household latrine coverage was 56.2% (95% CI 37.5–74.8%) and in rural areas coverage was 67.7% (95% CI 59.6–75.7%). Previously owning a latrine was reported by 12.7% (95% CI 8.9–16.5%) of respondents, of which 32.0% (95% CI 15.9–48.2%) had built a replacement. Latrine adopters were more likely to be male ( P P P = 0.004) and live in a rural area ( P P P
Heritable variation in pheromone response of the pink bollworm,Pectinophora gossypiella (Lepidoptera: Gelechiidae)

Heritability of variation in male pheromone response by pink bollworm moths,Pectinophora gossypiella (Saunders), was examined using a still-air, wing-fanning bioassay. Heritability (±SE) of overall responsiveness, as measured by the mean duration of wing fanning to the blend of pheromone components produced by females [44∶56 ratio of (Z, E)- to (Z, Z)-7,11-hexadecadienyl acetate], was 0.385 ± 0.095. Heritabilities of wingfanning duration to blends with 25 and 65%Z, E isomer were 0.377 ± 0.113 and −0.145 ± 0.103, respectively. These findings indicate an asymmetry in the genetic component of variation in response to pheromone blends with high and low proportions of theZ, E isomer. An index of response specificity for individual males was developed based on the response to an off-blend (either 25 or 65%Z, E isomer) relative to the response to the 44%Z, E blend. Heritabilities of response specificity were 0.117 ± 0.059 and −0.043 ± 0.067 for the 25 and 65%Z, E blends, respectively.
Ventricular hypertrophy and left atrial dilatation persist and are associated with reduced survival after valve replacement for aortic stenosis

Objectives We sought to understand the factors modulating left heart reverse remodeling after aortic valve replacement, the relationship between the preoperative symptoms and modulators of left heart remodeling, and their influence on long-term survival. Methods From October 1991 to January 2008, 4264 patients underwent primary aortic valve replacement for aortic stenosis. Changes in the time course of left ventricular reverse remodeling were assessed using 5740 postoperative transthoracic echocardiograms from 3841 patients. Results Left ventricular hypertrophy rapidly declined after surgery, from 137 ± 42 g/m 2 preoperatively to 115 ± 27 by 2 years and remained relatively constant but greater than the upper limit of normal. The most important risk factor for residual left ventricular hypertrophy was greater preoperative left ventricular hypertrophy ( P Conclusions Severe left ventricular hypertrophy with left atrial dilatation can develop from severe aortic stenosis, even without symptoms. These changes can persist, are associated with decreased long-term survival even after successful aortic valve replacement, and could be indications for early aortic valve replacement if supported by findings from an appropriate prospective study.
Generation and manipulation of multi-cycle terahertz pulses via optical rectification in poled lithium niobate

We demonstrate control of terahertz (THz) waves developing novel devices in the THz regime: THz pulse shapers. THz technology is a relatively unexplored subject, yet the importance of THz wave manipulation cannot be emphasized enough considering its potential application to THz imaging systems, ultrafast optical signal processing, ultrahigh-speed computing, quantum information science, nanotechnology, and chemical reaction dynamics among other areas. THz time-domain spectroscopy (THz-TDS) can assess the performance of the THz pulse shapers monitoring time-dependent THz wave propagation. THz-TDS permits precise measurements not only of the amplitude but also of the phase of THz waves, thus a comprehensive assessment of the THz devices can be achieved. The phase sensitivity is also vital to many applications such as high-contrast THz imaging and quantum control of semiconductor nanostructures. We develop arbitrary THz pulse generators synthesizing THz waveforms via optical rectification in pre-engineered domain structures of poled nonlinear crystals using femtosecond lasers. The terahertz waveforms coincide with the crystal domain structures. The one dimensional nonlinear wave equation simulates the experimental results with a good qualitative agreement. The ratio of the domain length to the optical pulse length in the crystal turns out to be the crucial limiting factor to generating optimum terahertz fields and preventing waveform distortion. Optical pulse shaping techniques is integrated into the THz pulse generators to extend the scope of THz pulse shaping control. Continuously tunable narrow-band THz pulses are generated in a fanned-out periodically-poled lithium niobate crystal. We measure the free induction decay of rotational transitions in gas-phase HCl molecules using the narrow-band THz pulses. The shape of the multi-cycle THz pulses is controlled by adjusting the relative time delay and intensity between the two optical pulses.
Quantitative Theory for Protein-Protein Interactions in a Crowded Environment

Protein-protein interactions play an essential role in many biological processes, including DNA transcription regulation, signal transduction, membrane-protein trafficking and immune response. The cellular medium is crowded with an ensemble of macromolecules, e.g., proteins, nucleic acids, sugars and lipids. These macromolecules can occupy as high as 30% of the cell volume and interact with proteins via van der Waals and electrostatic interactions, thereby affecting the stability and kinetics of multiprotein complexes. Experiments and simulations have shown that macromolecules increase the protein-binding affinity via the excluded volume effects, while the presence of attractive interactions between proteins and crowding agents decreases the binding affinity. Such competition between stabilizing effects by excluded volume and destabilizing effects by attractive interactions can complicate the interpretation of experimental data on protein-protein interactions in a crowded solution as well as in a living cell. Although theories based on the scaled particle theory have been successful to describe the excluded volume effects on the protein-binding equilibria, no quantitative theory has been attempted to describe the protein-protein interactions in a crowded solution with repulsive as well as attractive interactions. Here we develop a quantitative theory for protein-protein interactions in the presence of attractive crowding agents. Without any fitting parameter, the theory describes very well the simulation data of the protein-binding affinities for several protein complexes influenced by attractive crowding particles. The theory provides further insights into understanding of in vivo macromolecular crowding effects on protein-protein interactions.
Controlling the healthy worker survivor effect: an example of arsenic exposure and respiratory cancer.

OBJECTIVE--This investigation sought to examine whether methods proposed to control the healthy worker survivor effect would influence the shape or magnitude of the dose-response curve for respiratory cancer induced by arsenic. METHODS--Results from an unadjusted analysis are compared with results obtained by applying four different methods for control of the healthy worker survivor effect to data on arsenic exposure and respiratory cancer. The four methods are: exposure lag, adjustment for work status, cohort restriction, and the G null test. RESULTS--Cohort restriction gave erratic results depending upon the minimum years of follow up used. Exposure lag substantially increased the rate ratios and a non-linear shape (decreasing slope) compared with an unlagged analysis. Adjusting for work status (currently employed upsilon retired or otherwise not employed) yielded slightly higher rate ratios than an unadjusted analysis, with an overall shape similar to the baseline analysis. Results from the G null test procedure of Robins (1986), although not directly comparable with the baseline analysis, did show an adverse effect of exposure that seemed to reach a maximum when exposure was lagged between 10 and 20 years. CONCLUSIONS--All results confirm an adverse effect of arsenic exposure on respiratory cancer. In these data, it seems that the healthy worker survivor effect was not strong enough to mask the strong effect of arsenic exposure on respiratory cancer. Nevertheless, several methods show a stronger association between arsenic exposure and respiratory cancer after adjustment for the healthy worker survivor effect, suggesting that for weaker causal associations, studies not controlling for this source of bias will have low power to detect results. Although the G methods are theoretically the most unbiased, further work elucidating the validity of the assumptions underlying lagging, adjustment for work status, and the G methods are needed before clear recommendations can be made.
Linear network coding capacity region of 2-receiver MIMO broadcast packet erasure channels with feedback

This work studies the capacity of the 2-receiver multiple-input/multiple-output (MIMO) broadcast packet erasure channels (PECs) with channel output feedback, which is in contrast with the single-input/single-output setting of the existing works. Motivated by the immense success of linear network coding (LNC) in theory and in practice, this work focuses exclusively on LNC schemes and characterizes the LNC feedback capacity region (R∗ 1 , R∗ 2 ) of 2-receiver MIMO broadcast PECs. A new linear-space-based approach is proposed, which unifies the problems of finding a capacity outer bound and devising the achievability scheme into a single linear programming (LP) problem. Specifically, an LP solver is used to exhaustively search for the LNC scheme(s) with the best possible throughput, the result of which is thus guaranteed to attain the LNC feedback capacity.
The pricing of a round of golf: the inefficiency of membership fees revisited.

This article argues that the use of membership fees at shared facilities, such as private golf courses, is not per se evidence of inefficient pricing as implied by the club theory literature on variable usage. The author reconciles the inconsistency between the predictions of existing models and empirical evidence by accounting for members’ opportunity cost of time and the effect of congestion on members’ utility. In particular, this research shows that the simplified nature of congestion assumed in the literature ignores the positive externalities that members receive from a members-only club.
Dynamic simulation of doppler spectra of targets with rotating parts

We present the dynamic simulation results of the Doppler spectra of targets containing rotating parts based on first-principle electromagnetics computation. Our simulation examples include an inlet duct with a rotating compressor and a model helicopter with rotating blades. Such simulation results allow a detailed interpretation of the various scattering phenomenologies for radar target identification applications. © 1994 John Wiley & Sons, Inc.
Type II pneumocytes modulate surfactant production in response to cigarette smoke constituents: restoration by vitamins A and E.

Abstract This study was to evaluate the effects of cigarette smoke constituents upon type II pneumocyte surfactant production in vitro, and how vitamins A and E may alter the response. Freshly isolated type II pneumocytes from Sprague–Dawley rats were incubated 20 h in medium with fetal bovine serum that was or was not treated with cigarette smoke. The number of adherent cells was inversely related to the dose of smoke or benzo(a)pyrene. Despite the decreased number of treated cells, the total amount of surfactant per culture well was unchanged, whereas surfactant production per cell was significantly increased (P
Targeting nitric oxide signaling with nNOS inhibitors as a novel strategy for the therapy and prevention of human melanoma.

Abstract Aims: Our previous studies have shown that nitric oxide (NO) plays an important role in increasing the invasion and proliferation of human melanoma cells, suggesting that targeting NO signaling may facilitate therapy and prevention. Neuronal nitric oxide synthase (nNOS) is present in melanocytes, a cell type that originates from the neural crest. The aims of this study were to determine the role of nNOS in melanoma progression and the potential antitumor effects of novel synthesized nNOS inhibitors. Results: In vitro studies demonstrated abundant expression of nNOS in melanoma compared to melanocytes, which was inducible by ultraviolet radiation and was associated with increased NO generation. nNOS was also detected in melanoma biopsies that increased with disease stage. Knockdown of nNOS in melanoma cells diminished L-arginine-induced NO production; the metastatic capacity was also reduced as well as the levels of MMP-1, Bcl-2, JunD, and APE/Ref-1. Similar inhibition of NO and invasion potential...
Overview: fungal infections in the transplant patient

Fungal infection remains a major hurdle in solid organ transplantation. A variety of new antifungal agents have become available and new diagnostic tools are in development. This conference was convened to review current approaches to the prevention and treatment of fungal infection in transplantation. Among the keys to successful management of fungal infection are identification of patients at risk for infection (stratification), eradication or control of established infection in advance of transplantation, the demonstration of cure by radiologic and histopathologic means, and the use of surgical debridement, reduction in immune suppression, and fungicidal therapies whenever possible. The absence of sensitive diagnostic tools and standardization of antifungal susceptibility testing for the filamentous fungi are identified as major impediments to care in this area.
Piperidine derivatives. I. Preparation of piperidine-2,6-dicarboxylic acid and its N-methyl derivative.

A convenient preparation of piperidine-2,6-dicarboxylic acid and its N-methyl derivative has been described in detail and the literature pertaining to these compounds has been reviewed. Piperidine-2,6-dicarboxylic acid is prepared by the catalytic reduction of pyridine-2,6-dicarboxylic acid. The preparation of the N-methyl derivative involves the use of formic acid and formaldehyde. Comparison of the melting points of the compounds made and their derivatives with earlier work points to the cis configuration for the compounds.
Effect of 30 per cent maternal nutrient restriction from 0.16 to 0.5 gestation on fetal baboon kidney gene expression

Previous studies in rodents and sheep show that maternal nutrient restriction during pregnancy alters fetal renal development. To date, no studies using fetal baboon RNA with human Affymetrix gene chips have been published. In the present study we have (1) evaluated the specificity of the Affymetrix human gene array ‘Laboratory on a Chip’ system for use with fetal baboon mRNA and (2) investigated the effects of moderate maternal global nutrient restriction (NR; 70% of ad libitum animals) from early (30 days gestation (dG)) to mid-gestation (90 dG; term = 184 dG) on the fetal baboon kidney. Morphometric and blood measurements were made on 12 non-pregnant baboons before they were bred. All baboons were fed ad libitum until 30 days pregnant, at which time six control baboons continued to feed ad libitum (control – C) while six received 70% of the C diet on a weight adjusted basis. Fetal kidneys were collected following caesarean section at 90 dG, with samples flash frozen and fixed for histological assessment. Fetal hip circumference was decreased in the NR group (68 ± 2 versus 75 ± 2 mm), while fetal body weight and all other measurements of fetal size were not different between C and NR at 90 dG. Maternal body weight was decreased in the NR group (12.16 ± 0.34 versus 13.73 ± 0.55 kg). Having established the specificity of the Affymetrix system for fetal baboon mRNA, gene expression profiling of fetal kidneys in the context of our maternal nutrient restriction protocol shows that NR resulted in a down-regulation of genes in pathways related to RNA, DNA and protein biosynthesis, metabolism and catabolism. In contrast, genes in cell signal transduction, communication and transport pathways were up-regulated in the NR group. These changes indicate that even a moderate level of maternal global NR impacts fetal renal gene pathways. Our histological assessment of renal structure indicates decreased tubule density within the cortex of NR kidneys compared with controls. The number of glomerular cross-sections per unit area were unaffected by NR, suggesting that tubule tortuosity and/or tubule length was decreased in the NR kidney. Taken together the changes indicate that NR results in accelerated fetal renal differentiation. The negative impact of poor maternal nutrition on the fetal kidney may therefore be in part due to shortening of critical phases of renal growth resulting in decreased functional capacity in later life. These findings may have important implications for postnatal renal function, thereby contributing to the observed increased predisposition to hypertension and renal disease in the offspring of nutrient restricted mothers.
RELATIVISTIC CORRECTIONS IN A SERIES OF HELIUM EXCITED STATES

Abstract Relativistic corrections to order (υ/ c ) 2 are applied to the helium excited states 2 1,3 P, 3 1,3 D,…, 8 1,3 K. Simple correlated open-shell wavefunctions are employed and the Breit operators H 1 through H 5 treated as perturbations. Account is also taken of mass polarization and lowest-order one electron Lamb shift. The energies thus calculated agree with experiment to within 2.2 cm −1 or better.
Nitrogen‐stimulated potassium influx into maize roots: differential response of components resistant and sensitive to ambient ammonium

Abstract Potassium (86Rb) influx from 200 mmol m −3 KCl into dark grown, decapitated maize seedlings 6 d old) was stimulated by nitrate pretreatment. The stimulus was clearly evident by 6h exposure to nitrate and required 12–24 h for maximal expression. Decay of the nitrate-stimulated potassium influx was more than 50% complete within 3 h after transfer to nitrogen-free solutions. The stimulation of potassium influx was entirely accounted for by an increase in the influx component that was resistant to inhibition by presence of 200 mmol m−3 ambient ammonium. In contrast, the component of potassium influx that was sensitive to inhibition by ambient ammonium was unaffected by nitrate pretreatment. Exposure to the glutamine synthetase inhibitor L-methionine-dl-sulphoximine (MSX) during nitrate pretreatment stimulated the resistant component but the sensitive component was nearly eliminated. Pretreatment with ammonium increased the resistant component of potassium influx within 3 h, i.e. before it was increased by nitrate pretreatment, but the sensitive component was concomitantly restricted. The latter recovered partially during extended pretreatment with ammonium. The data indicate that the resistant component responded positively to increases in tissue ammonium concentrations whereas the sensitive component was unaffected by tissue ammonium except at concentrations in excess of 10μmol g−1. Ammonium influx was also stimulated by nitrate pretreatment and to a greater extent than potassium influx. Presence of MSX with nitrate during pretreatment resulted in a further stimulation in ammonium influx. The parallel increases in root ammonium concentrations with the two pretreatments imply that part of the increase in ammonium influx was a consequnce of increased counter-transport with endogenous ammonium.
Control of particle size in dispersion polymerization of methyl methacrylate

Poly(methyl methacrylate) (PMMA) particles ranging in diameter from 2 to 10 μm were prepared by dispersion polymerization. The effects of various polymerization parameters on the size and monodispersity were systematically investigated. The particle size was found to increase with increasing polymerization temperature, concentration and decomposition rate of the initiator, and solvency of the dispersion medium. It also increased with increasing concentration and molecular weight of the polymeric stabilizer, poly(vinyl pyrrolidone) (PVP). As the monomer concentration was increased from 5 to 20 wt %, a minimum was found in the particle size at a monomer concentration of 10 wt %. A costabilizer was found to be necessary for preparing monodisperse particles at stabilizer concentrations below 2 wt %. A recycling experiment showed that the consumption of PVP was quite small in each cycle and the residual materials in this system could be reused readily. © 1993 John Wiley & Sons, Inc.
A Sequential Stopping Rule for a Steady-State Simulation Based on Time-Series Forecasting:

A sequential stopping procedure should collect enough steady-state data to overwhelm the influence of initial transient bias without requiring initial data truncation. The initial transient negatively affects the efficiency of the sequential procedure, but from a practical point of view, eliminating the difficulty of determining the data truncation point can lead to a more easily implemented algorithm for determining the appropriate length of a simulation run. A sequential stopping rule is presented that uses a time-series forecasting procedure to determine appropriate trade-offs between the efficiency and simplicity of the estimate of cycle time for a relevant constant mean process. Results show that the proposed sequential stopping rule terminates a simulation output process at a point when a stable estimate is obtained. Furthermore, the rule performs as well as the crossings-of-means data truncation technique yet is easier to implement.
DNA.EXE: A Sequence Comparison between the Human Genome and Computer Code

This study presents evidence that executable computer programs and human genomes contain similar patterns of repetitive code. When viewed with sequence visualization tools, these similarities are both striking and pervasive. The primary similarities are listed in order of scale: (1) homopolymers, (2) tandem repeats, (3) distributed repeats, (4) isochores, (5) and entire chromosome/file organization. Most strikingly, data visualization reveals that executable codes regularly make extensive use of tandem repeats which exhibit similar visual patterns as seen in higher genomes. In biology these tandem repeat patterns are normally attributed to replication errors, insertions, deletions, and substitutions. Similarly, on a larger scale, executable codes display regions with different ratios of 1’s and 0’s which parallel the isochore patterns within chromosomes, caused by local variation in the number of A/T vs. G/C. Further, blocks of data are stored at the beginning or end of a file, while the primary instructions occupy the middle of a file. This creates the same organizational patterns observed in human chromosome arms, where repetitive sequences are grouped near the telomeres and centromeres. I propose that these similarities can be explained by universal constraints in efficient information encoding and execution. The genome may be viewed as the executable program that encodes life. Given the evidence that computer programs and genomes use many of the same patterns of organization, despite having very different context, it should be informative to explore the ways in which knowledge of computer architecture can be applied to biology and vice versa.
Selfish behavior and stability of the internet: a game-theoretic analysis of TCP

For years, the conventional wisdom [7, 22] has been that the continued stability of the Internet depends on the widespread deployment of "socially responsible" congestion control. In this paper, we seek to answer the following fundamental question: If network end-points behaved in a selfish manner, would the stability of the Internet be endangered?.We evaluate the impact of greedy end-point behavior through a game-theoretic analysis of TCP. In this "TCP Game" each flowattempts to maximize the throughput it achieves by modifying its congestion control behavior. We use a combination of analysis and simulation to determine the Nash Equilibrium of this game. Our question then reduces to whether the network operates efficiently at these Nash equilibria.Our findings are twofold. First, in more traditional environments -- where end-points use TCP Reno-style loss recovery and routers use drop-tail queues -- the Nash Equilibria are reasonably efficient. However, when endpoints use more recent variations of TCP (e.g., SACK) and routers employ either RED or drop-tail queues, the Nash equilibria are very inefficient. This suggests that the Internet of the past could remain stable in the face of greedy end-user behavior, but the Internet of today is vulnerable to such behavior. Second, we find that restoring the efficiency of the Nash equilibria in these settings does not require heavy-weight packet scheduling techniques (e.g., Fair Queuing) but instead can be done with a very simple stateless mechanism based on CHOKe [21].
Lactate and glycogen metabolism in the lizard Dipsosaurus dorsalis following exhaustive exercise

We evaluated the metabolic mechanisms by which the iguanid lizard Dipsosaurus dorsalis deals with the lactate which accumulates during vigorous exercise. Fasted, cannulated lizards were run for 5 min on a treadmill at 40°C, which elevated whole-body lactate to 24 mmol l−1 and depleted hindlimb glycogen to 70% of resting levels. Oxygen consumption increased fivefold and respiratory exchange ratios approached 2.0. Exhausted animals were then injected intravenously with either [U-14C]lactate or [U-14C]glucose, and allowed to recover quietly on the treadmill at 40°C. After 2h, 79% of the accumulated lactate had been removed and hindlimb muscle glycogen stores had returned to pre-exercise levels. Although blood glucose remained unchanged at 8.6 ± 0.27 mmol l−1 throughout the recovery period, whole-body glucose increased significantly from 1.6 ± 0.23 to 5.5 ± 0.38 mmol l−1 (P
Comparing E-Mail and Synchronous Conferencing in Online Peer Response

This article details study results comparing e-mail and synchronous conferencing as vehicles for online peer response. The study draws on Clark and Brennan's theory of communicative “grounding,” which predicts that participants use different techniques for achieving mutual knowledge depending on the type of media being used. Content analysis of transcripts from both types of response sessions showed that when using e-mail, students made significantly greater reference to documents, their contents, and rhetorical contexts than when using synchronous conferencing. Students made greater reference to both writing and response tasks using synchronous chats than when using e-mail. Students' individual media preferences showed no significant differences in terms of message formulation, reception, and usefulness of comments in aiding revision. However, in a forced comparison scale, students rated e-mail more serious and helpful than chats, which were then rated more playful than e-mail. Implications of the study'...
Tissue-specific coordinate regulation of enzymes of cholesterol biosynthesis: sciatic nerve versus liver

Exposure of weanling rats to a diet containing the element tellurium results in specific inhibition of squalene epoxidase, an obligate enzyme in cholesterol biosynthesis. Liver responds to the resulting intracellular sterol deficit by up-regulating, in parallel and to the same extent, expression of mRNA for squalene epoxidase and for HMG-CoA reductase, the major rate-limiting enzyme in the pathway. This increased mRNA expression, coupled with additional translational and posttranslational activation of the pathway allows normal levels of cholesterol synthesis in liver despite tellurium-induced inhibition of squalene epoxidase. The response to tellurium challenge in sciatic nerve is very different. In this tissue, cholesterol synthesis is prominent because of the large amount of cholesterol required for synthesis and maintenance of myelin. Although nerve shows an initial (at 1 day) up-regulation of mRNA expression for both enzymes in response to tellurium exposure, this is followed quickly by parallel down-regulation of both enzymes, in concert with down-regulation of mRNA expression for myelin proteins. We suggest that the tellurium-induced deficit in sterols leads to a coordinate down-regulation of synthesis of myelin components. The initial early up-regulation of cholesterol biosynthesis in sciatic nerve due to the cholesterol deficit is countered by down-regulation which is coordinated with overall control of the program of myelin assembly. This tissue-specific control of cholesterol synthesis in sciatic nerve is a point of vulnerability to toxicants, and may be related to the need for coordinate synthesis of all components of myelin.
Copper intake and assessment of copper status.

The diagnosis of marginal copper deficiency has not been perfected despite an increased understanding of the physiologic roles of copper. The use of nonstandardized procedures and the effects of factors other than copper nutriture have impeded identification of an ideal indicator of copper nutritional status in humans. A review of studies of experimental copper deprivation conducted in adult humans over the past 12 y indicated that between 1.0 and 1.25 mg Cu/d is needed by adults for copper maintenance for periods of up to 6 mo and that ≤2.6 mg Cu/d for periods of up to 42 d is not sufficient for recovery from copper deprivation. Copper-containing enzymes in blood cells, such as erythrocyte superoxide dismutase and platelet cytochrome-c oxidase, may be better indicators of metabolically active copper and copper stores than plasma concentrations of copper or ceruloplasmin because the enzyme activities are sensitive to changes in copper stores and are not as sensitive to factors not related to copper nutriture.
Can Community Policing Help the Truly Disadvantaged

Community policing advocates argue that reforms designed to break down barriers between police and citizens can produce favorable outcomes. The authors test a series of related hypotheses in a multivariate context by using four independent data sources— community surveys, patrol officer interviews, Census Bureau, and police crime records— to estimate hierarchical linear models. The results show that citizens who perceive police partnerships favorably report fewer problems related to incivilities and also express higher levels of safety. Findings from models including cross-level interaction terms indicate that the positive outcomes associated with police partnerships are not restricted to citizens residing in affluent neighborhoods. In our ecological analysis, we find that police-community collaboration is associated with higher aggregate quality of life assessments and that community policing as a form of public social control mediates the adverse effects of concentrated disadvantage. The findings suppor...
Fabrication and characterization of multi-level hierarchical surfaces

A nanostructured surface may exhibit low adhesion or high adhesion depending upon fibrillar density, and it presents the possibility of realizing eco-friendly surface structures with desirable adhesion by mimicking the mechanics of fibrillar adhesive surfaces of biological systems. The current research uses a patterning technique to fabricate smart adhesion surfaces: one-, two- and three-level hierarchical synthetic adhesive structure surfaces with various fibrillar densities and diameters. The contact angles and contact angle hysteresis were measured to characterize the wettability. A conventional and a glass ball attached to an atomic force microscope (AFM) tip were used to obtain the adhesive forces via force–distance curves and to study the buckling behavior of a single fiber on the hierarchical structures.
High harmonic generation in SF6: Raman-excited vibrational quantum beats

In a recent experiment (Wagner et al 2006 Proc. Natl Acad. Sci. USA 103 13279) on SF6, a high-harmonic generating laser pulse is preceded by a pump pulse which stimulates Raman-active modes in the molecule. Varying the time delay between the two pulses modulates high harmonic intensity, with frequencies equal to the vibration frequencies of the Raman-active modes. We propose an explanation of this modulation as a quantum interference between competing pathways that occurs via adjacent vibrational states of the molecule. The Raman and high harmonic processes act as beamsplitters, producing vibrational quantum beats among the Raman-active vibrational modes that are excited by the first pulse. We present an improved version of the widely used three-step model, which tracks the evolution of the molecule's vibrational state and employs a rigorous treatment of the complicated electron–molecule recombination.
Experimental study of a novel adaptive controller for active vibration isolation

Adaptive control has drawn attention for active vibration isolation and vehicle suspensions because of its potential to perform in the presence of nonlinearities and unknown or time-varying parameters. Model-reference adaptive control has been used to force the plant to track the states or certain outputs of the ideal reference model. In this paper, we study the application of a new adaptive approach, "model-reaching" adaptive control, to achieve the ideal multi-DOF isolation effect of a skyhook target without using a model reference. We define a dynamic manifold in terms of the states of the plant, rather than the error of the plant tracking of the reference. Then we derive an adaptive control law based on Lyapunov analysis to make the isolation system reach the dynamic manifold while estimating the unknown parameters. Compared with the conventional model-reference adaptive algorithm for vibration isolation, the proposed adaptive control eliminates the need for measurement of base vibration and has the potential to guarantee the transient performance. The effects of geophone dynamics are also discussed. We carry out an experimental investigation based on a realistic plant with friction, demonstrate the effectiveness of the proposed adaptive control, and show that the target dynamics of the skyhook isolator are attained. The convergence of the parameter adaptation in the experiment is also examined.
Long-term function of NCGT vascular conduits in a multicenter trial: evaluation of physical chemical parameters.

Our experience with the NCGT graft has now encompassed 12 years in experimental animals and 4.5 years clinical experience with 134 grafts in man. It has previously been suggested that vessel wall structure, interface-charge, electric potential, and polarity of the blood intimal interface appear critical in the prevention of intravascular thrombosis in all vascular prosthetic bypass grafts.This concept has now been confirmed using ferritin, colloidal iron and fluorescamine intimal labelling. These provide a quantitative spacial characterization of the surface charges of several grafts, including the NCGT graft.Study indicates that each step in the production of the NCGT graft results in a cumulative increase in the structured negative charge of the vascular interface. The more dense the structured negative charge of the prosthesis, the more resistant is the graft to short and long-term thrombosis in experimental animals and man. The experience has been confirmed with a comparative analysis of implantation ...
Analysis of Antiretrovirals in Single Hair Strands for Evaluation of Drug Adherence with Infrared-Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry Imaging

Adherence to a drug regimen can be a strong predictor of health outcomes, and validated measures of adherence are necessary at all stages of therapy from drug development to prescription. Many of the existing metrics of drug adherence (e.g., self-report, pill counts, blood monitoring) have limitations, and analysis of hair strands has recently emerged as an objective alternative. Traditional methods of hair analysis based on LC-MS/MS (segmenting strands at ≥1 cm length) are not capable of preserving a temporal record of drug intake at higher resolution than approximately 1 month. Here, we evaluated the detectability of HIV antiretrovirals (ARVs) in hair from a range of drug classes using infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging (MSI) with 100 μm resolution. Infrared laser desorption of hair strands was shown to penetrate into the strand cortex, allowing direct measurement by MSI without analyte extraction. Using optimized desorption conditions, a linear correlation between IR-MALDESI ion abundance and LC-MS/MS response was observed for six common ARVs with estimated limits of detection less than or equal to 1.6 ng/mg hair. The distribution of efavirenz (EFV) was then monitored in a series of hair strands collected from HIV infected, virologically suppressed patients. Because of the role hair melanin plays in accumulation of basic drugs (like most ARVs), an MSI method to quantify the melanin biomarker pyrrole-2,3,5-tricarboxylic acid (PTCA) was evaluated as a means of normalizing drug response between patients to develop broadly applicable adherence criteria.
Robust Kalman filter design for predictive wind shear detection

Severe, low-altitude wind shear is a threat to aviation safety. Airborne sensors under development measure the radial component of wind along a line directly in front of an aircraft. In this paper, optimal estimation theory is used to define a detection algorithm to warn of hazardous wind shear from these sensors. To achieve robustness, a wind shear detection algorithm must distinguish threatening wind shear from less hazardous gustiness, despite variations in wind shear structure. This paper presents statistical analysis methods to refine wind shear detection algorithm robustness. Computational methods predict the ability to warn of severe wind shear and avoid false warning. Comparative capability of the detection algorithm as a function of its design parameters is determined, identifying designs that provide robust detection of severe wind shear.