cssi/SciSciGPT-SciSciNet huggingface dataset:
A Quantitative Study of Oxygen as a Metabolic Regulator

An acute reduction in oxygen delivery to a tissue is associated with metabolic changes aimed at maintaining ATP homeostasis. However, given the complexity of the human bioenergetic system, it is difficult to determine quantitatively how cellular metabolic processes interact to maintain ATP homeostasis during stress (e.g., hypoxia, ischemia, and exercise). In particular, we are interested in determining mechanisms relating cellular oxygen concentration to observed metabolic responses at the cellular, tissue, organ, and whole body levels and in quantifying how changes in tissue oxygen availability affect the pathways of ATP synthesis and the metabolites that control these pathways. In this study, we extend a previously developed mathematical model of human bioenergetics, to provide a physicochemical framework that permits quantitative understanding of oxygen as a metabolic regulator. Specifically, the enhancement--sensitivity analysis--permits studying the effects of variations in tissue oxygenation and parameters controlling cellular respiration on glycolysis, lactate production, and pyruvate oxidation. The analysis can distinguish between parameters that must be determined accurately and those that require less precision, based on their effects on model predictions. This capability may prove to be important in optimizing experimental design, thus reducing use of animals.
The modified superior based pharyngeal flap technique

There is little in the literature on the topographic and/or applied surgical anatomy related to superior based pharyngeal flap surgery. Herein we report on the applied surgical anatomy of pharyngeal flap surgery, especially as it applies to critical anatomic relationships to vessels, muscles, and nerves.
PUBLIC CHOICE AND GAINING FROM GOVERNMENT

This chapter describes the public use of private interest and the gaining from government. In a society that relies on private enterprise and market incentives to carry out most productive activity, the problem of public intervention is a real one. There remains a critical choice to be made: should intervention be carried out by grafting a specific command-and-control module—a regulatory apparatus—onto the system of private enterprise, or by modifying the informational flow, institutional structure, or incentive pattern of that private system. However, both these approaches seem inappropriate to every situation. From a long-range standpoint, the effectiveness of social intervention in a number of important areas depends critically on heeding this lesson. Much of the economic literature on pollution control, for example, stresses the role of economic incentives to achieve static efficiency in control measures, that is, the use of existing technology in a way that reaches environmental goals at least cost. In the long run, however, the future of society is going to hinge on the discovery and adoption of ever-improving technologies to reduce the environmental consequences of expanding production.
The inhibition of ferroxidase by trivalent and other metal ions.

Abstract The inhibitory effects of trivalent and other metal ions on ferroxidase (ceruloplasmin EC 1.12.3.1.) activity were investigated. All trivalent cations tested inhibited ferroxidase activity but the strongest inhibitors had an ionic radius of 0.81 A or less. The inhibition by Al(III) was found to be mixed competitive and uncompetitive with respect to the substrate, Fe(II). The uncompetitive feature of the inhibition was not due to competition by Al(III) with the other substrate, oxygen. A mechanism for the mixed inhibition by Al(III) is proposed consistent with these results. A comparison of the strong cationic inhibitors provides the following metal ion series in order of decreasing effectiveness of inhibition: In(III) g ZrO(II) g Al(III) g Sc(III) g Ga(III)
Symmetric logic of proofs

The Logic of Proofs LP captures the invariant propositional properties of proof predicates t is a proof of F with a set of operations on proofs sufficient for realizing the whole modal logic S4 and hence the intuitionistic logic IPC. Some intuitive properties of proofs, however, are not invariant and hence not present in LP. For example, the choice function '+' in LP, which is specified by the condition s:F∨t:F → (s+t):F, is not necessarily symmetric. In this paper, we introduce an extension of the Logic of Proofs, SLP, which incorporates natural properties of the standard proof predicate in Peano Arithmetic: t is a code of a derivation containing F, including the symmetry of Choice. We show that SLP produces Brouwer-Heyting-Kolmogorov proofs with a rich structure, which can be useful for applications in epistemic logic and other areas.
Reexamination of relaxation of spins due to a magnetic field gradient: Identity of the Redfield and Torrey theories

There is an extensive literature on magnetic-gradient-induced spin relaxation. Cates, Schaefer, and Happer, in a seminal publication, have solved the problem in the regime where diffusion theory (the Torrey equation) is applicable using an expansion of the density matrix in diffusion equation eigenfunctions and angular momentum tensors. McGregor has solved the problem in the same regime using a slightly more general formulation using the Redfield theory formulated in terms of the autocorrelation function of the fluctuating field seen by the spins and calculating the correlation functions using the diffusion-theory Green's function. The results of both calculations were shown to agree for a special case. In the present work, we show that the eigenfunction expansion of the Torrey equation yields the expansion of the Green's function for the diffusion equation, thus showing the identity of this approach with that of the Redfield theory. The general solution can also be obtained directly from the Torrey equation for the density matrix. Thus, the physical content of the Redfield and Torrey approaches are identical. We then introduce a more general expression for the position autocorrelation function of particles moving in a closed cell, extending the range of applicability of the theory.
Acute alcohol produces hypoxia directly in rat liver tissue in vivo: role of Kupffer cells

Previous studies using liver slices and isolated perfused rat liver have suggested that ethanol causes hypoxia by increasing oxygen consumption. However, ethanol also increases blood flow to the liver, a phenomenon that may counteract the effects of hypermetabolism by increasing oxygen delivery. Thus whether ethanol causes hypoxia in vivo remains unclear. To clarify this important point, female Sprague-Dawley rats (100-125 g) simultaneously received pimonidazole (120 mg/kg ip), a 2-nitroimidazole hypoxia marker, and one large dose of ethanol (5 g/kg ig), which increase hepatic oxygen uptake dramatically and elevate ethanol metabolism (swift increase in alcohol metabolism) in 2-3 h. After 2 h, ethanol significantly increased the accumulation of bound pimonidazole in pericentral regions of the liver lobule. Treatment of animals with the Kupffer cell-specific toxicant, GdCl3 (10 mg/kg iv, 24 h before experiment), blocked ethanol-induced increases in pimonidazole binding. It is concluded that one large dose of ethanol causes pericentral hypoxia in rat liver tissue in vivo and that Kupffer cells are involved.
Incremental value of 128x128 matrix acquisition on Tc-99m myocardial perfusion SPECT/CT

2031 Objectives To assess the incremental contribution of 128 x128 acquisitions to improving the diagnostic quality of Tc-99m SPECT/CT performed at rest and stress for evaluation of coronary artery disease. Methods Thirty patients referred for myocardial perfusion SPECT/CT underwent imaging at rest and stress with both 64x64 and 128x128 matrix imaging. All patients received 10 mCi Tc-99m sestamibi for rest and 30 mCi Tc-99m sestamibi for stress with CT attenuation correction. Acquisition for 64x64 matrix were 20 seconds a stop for both rest and stress images.128x128 matrix acquisition were 35 seconds a stop for rest and 20 seconds a stop for stress. Stress test was preformed by treadmill exercise or by pharmacologic stress using regadenoson. All data was processed with iterative reconstruction and CT attenuation correction. Images sets were then reviewed for diagnostic quality by physicians experienced in clinical SPECT/CT. Results 128x128 images sets consistently scored higher then 64x64 matrix sets in overall image quality. The primary improvement was with the number of useable slices through the myocardium, which in turn helped with the delineation of epi/endocardial surfaces in all myocardial segments. This allowed more accurate clinical estimates of extent of ischemia or scar. Using available quantitative software, 128 matrix sets also gave better tracking of endocardial edges and apex/base limits in ECG-gated images. Conclusions Despite minimally longer acquisition times for resting images, 128x128 matrix adds both qualitative and quantitative image quality improvements in Tc-99m myocardial perfusion
Effect of training on lactate/ventilatory thresholds: a meta-analysis.

ABSTRACTThe purpose of the investigation was to determine the effect of exercise training intensity on the lactate and ventilatory thresholds in sedentary and in active subjects using meta-analysis procedures. The original analyses included 85 study groups from 34 studies. The dependent variable was
Flame Atomic Absorption Spectroscopy Using a Single-Mode Laser Diode as the Line Source

The laser diode recently has been applied to atomic spectroscopy in laser-enhanced ionization spectroscopy, laser-excited atomic fluorescence spectroscopy, resonance ionization mass spectrometry, and atomic absorption spectroscopy (AAS). Its attractive features include its having a low cost and being compact and tunable. Its major limitation is that commercial laser diodes are available only for fundamental wavelengths over the range of 670 to 1550 nm, and the tunability covers only several nanometers. In the AA investigation, a single-mode laser diode was used as the line source. Background correction was achieved by detuning the radiation to an off-resonance position; and the linear dynamic range could be extended by using the shoulder portion of the resonance line. Simultaneous multielement detection and internal standardization could be accomplished by the simultaneous use of several laser diodes. The atom reservoir employed was a graphite furnace and the detection spectrometer was a Fourier analyzer. We report here our observation of a single-mode laser diode used as the line source in flame AAS, with a simple, low-resolution monochromator and photomultiplier tube for detection. A multimode laser diode flame AAS has been reported in a separate paper.
An O(N) direct volume IE solver with a rank-minimized ℋ 2 -representation for large-scale 3-D circuit extraction in inhomogeneous materials

A linear-complexity direct matrix solution with a minimal-rank representation for the volume integral equation (VIE) is developed for the fullwave extraction of general 3-D circuits, containing arbitrarily shaped lossy conductors with inhomogeneous dielectrics. Numerical simulations of large-scale 3-D circuits involving millions of unknowns and comparisons with state-of-the-art VIE solvers have demonstrated the accuracy and efficiency of the proposed rank-minimized direct VIE solver.
Determination of sublimation rate of 2,4,6-trinitrotoluene (TNT) nano thin films using UV-absorbance spectroscopy

We report the in situ measurements of the sublimation rate and activation energy of continuous nanofilms of 2,4,6-trinitrotoluene (TNT) in air using UV absorbance spectroscopy. The films were prepared using acetone-dissolved TNT by simple spin coating deposition technique. Unlike traditional mass loss techniques, this new method is independent of the surface area of the sample which contributes to errors in determining physical parameters accurately in both bulk and thin films of materials. The calculated activation energy and temperature-dependent sublimation rates agree well with the reported values for TNT thin films. The results suggest that UV absorbance spectroscopy is an efficient tool in measuring thermodynamic properties in the nanometer scale for materials with absorbance in the UV region of the electromagnetic spectrum.
Fire hydrant efficiency measurements

Fire hydrant flow rates are a function of the difference between static and residual pressures. A meter, based on that relationship, has been designed to indicate to the pump operator the percent of available flow remaining.
Influence of Client-Based Subsidies on the Market for Child Care.

Federal support for child care subsidies targeted to poor households has grown dramatically in recent years. The analysis presented here examines the impact of such subsidies on child care fees charged to aU clients using Missouri data on provider fees and subsidy payments. It is found that patterns for fees and subsidies across providers imply that child care markets are largely competitive. Growth in subsidies observed over the period 1991-1993 increased fees and, by inference, improved quality for subsidized clients. Subsidies also induced an increase in fees for clients not covered by subsidies, an increase most likely due to the cost of expanding the child care market. Implementation of federal legislation has resulted in a dramatic increase in child care subsidies available to low income families.' Moreover, recent welfare reforms have focused on work requirements and lifetime limits on public assistance which increasingly necessitate the provision of child care to low-income families. New federal legislation substitutes block grants for many existing programs and repeals requirements for states to fund early childhood development programs. This means decision making regarding levels
Subwavelength grating structures in planar waveguide facets for modified reflectivity

We demonstrate experimentally and by simulations the use of subwavelength grating patterns on the facets of planar waveguides as a means of modifying facet reflectivity over a wide range of values, from antireflective to highly reflective. An antireflective structure can be obtained from a gradient index effect with triangular gratings. Square gratings can be used to obtain either antireflective or highly reflective facets by an interference effect. Finite difference time domain simulations and calculations based on effective medium theory show that reflectivities well below 1% can be achieved with triangular gratings. Experimentally, facet reflectivities as low as 2.0% and 2.4% for the fundamental TE and TM waveguide modes, respectively, are demonstrated for light of 1.55 μm wavelength in silicon-on-insulator ridge waveguides. The experimental results are in good agreement with both effective medium theory and finite difference time domain simulations. The polarization dependence of the effects is also discussed in detail.
A rational design of cosolvent exfoliation of layered materials by directly probing liquid–solid interaction

Exfoliation of layered materials into mono- or few-layers is desirable for both fundamental studies and practical applications. Here, the authors show that Young's equation can be used to predict the optimal cosolvent concentration for the effective exfoliation of graphite and molybdenum disulphide.
Simulation of large scale networks III: loosely-coordinated, distributed, packet-level simulation of large-scale networks

The complexity and dynamics of the Internet is driving the demand for scalable and efficient network simulation. In this paper, we describe a novel approach that partitions the networks into domains and simulation time into intervals. Each domain is simulated independently of and concurrently with the others with only local domain information over the same simulated time interval. At the end of each interval, global routing information, packet delays and drop rates for each inter-domain flow are exchanged between domain simulators. When the exchanged information converges to the value within a prescribed precision all simulators progress to the next simulated time interval. This approach allows the parallelization with infrequent synchronization, and achieves significant simulation speedups. Such a solution supports simulations of large-scale networks on distributed machines with modest memory size.
Variations in the social networks of forest owners: The effect of management activity, resource professionals, and ownership size

Social networks play an important role in the communication of information among forest owners and how owners process that information in making land management decisions. This article examines variations in the social network characteristics of family forest owners using survey data and interviews with 42 owners in south-central Indiana. We examine how network structure and content vary by harvesting activity, information sources, ownership attributes, sociodemographic characteristics, and location. Quantitative measures of network size and diversity, along with a qualitative understanding of network content and function are discussed and compared for active and passive forest managers. We find that active managers (people who had a recent timber harvest) had at least twice as many social ties related to forest management compared to passive managers, particularly after accounting for parcel ownership size, forest area, and total landholding size. Learning and service were the main functions of these networks, with learning being the most frequently cited reason for talking to others regardless of the management profile of forest owners. The study contributes to a growing interest in mixed-methods approaches to network studies and research on social networks in private forestry.
Cloning and sequence analysis of a catechol 2,3-dioxygenase gene from the nitrobenzene-degrading strain Comamonas sp JS765

sp strain JS765 utilizes nitrobenzene as a carbon and nitrogen source. The initial attack on nitrobenzene is carried out by nitrobenzene 1,2-dioxygenase, which converts nitrobenzene to an unstable nitrohydrodiol that spontaneously decomposes to form catechol and nitrite. Catechol is then degraded via a meta cleavage pathway. We now report the cloning of a DNA fragment carrying a catechol 2,3-dioxygenase gene from JS765. Nucleotide sequence analysis revealed three open reading frames (ORFs) predicted to encode proteins of 33.6, 13.0, and 35.0 kDa. Homology searches of the deduced amino acid sequences of three proteins suggested that ORF1 encodes a LysR-type transcriptional regulator, ORF2 encodes a XylT-type ferredoxin, and ORF3 encodes a catechol 2,3-dioxygenase. The putative regulatory gene, designated cdoR, is divergently transcribed from the ferredoxin and catechol dioxygenase genes, cdoT and cdoE, respectively. The catechol 2,3-dioxygenase is most similar in amino acid sequence to the I.2.C subfamily of extradiol dioxygenases which include 3-methylcatechol 2,3-dioxygenase from the aniline- and toluidine-degrading Pseudomonas putida UCC2, TbuE from the toluene monooxygenase pathway of Pseudomonas pickettii PKO1 and catechol 2,3-dioxygenase II from the TOL plasmid pWW15. The substrate range of the catechol 2,3-dioxygenase produced by the recombinant E. coli strains was very similar to that of the enzyme present in nitrobenzene-grown JS765, suggesting that we have cloned the catechol 2,3-dioxygenase gene required for nitrobenzene degradation.
Charged dust dynamics: Orbital resonance due to planetary shadows

The dynamics of a weakly charged dust grain orbiting in the equatorial plane of a planet surrounded by a rigidly corotating magnetospehre is examined. It is shown that an introduction of an effectilve 1D potential causes a perturbation due to electrostatic forces, which induces a motion of the pericenter, similar to the effect of the planetary oblateness. A case is examined where the charge varies periodically due to the modulation of the photoelectron current occurring as the grain enters and leaves the planetary shadow, causing the electromagnetic perturbation to resonate with the orbital period and to modify the size and eccentricity of the orbit. This effect is demonstrated both numerically and analytically for small grains comprising the Jovian ring, showing that their resulting changes are periodic, and their amplitude is much larger than that of the periodic changes due to light-pressure perturbation or the secular changes due to resonant charge variations that develop over a comparable time span.
Bubbles in food commodity markets: Four decades of evidence ☆

Abstract We use daily prices from individual futures contracts to test whether speculative bubbles exist in 12 agricultural markets and to identify whether patterns of bubble behavior exist over time. The samples begin as far back as 1970 and run through 2011. The findings demonstrate that all 12 agricultural markets experienced multiple periods of price explosiveness. However, bubble episodes represent a very small portion—between 1.5 and 2%—of price behavior during the 42-year period. In addition, most bubbles are short-lived with 80–90% lasting fewer than 10 days. Though receiving far less attention, negative bubbles contribute significantly to price behavior, accounting for more than one-third of explosive episodes. Markets over-react during both positive and negative explosive episodes, leading to a correction as they return to a random walk. This adjustment back to fundamental values is most pronounced with positive bubbles particularly in the earlier part of the sample. While the magnitudes of the corrections are generally small, there were a few instances of significant increases in prices and large over-reactions, most notably in the softs (e.g., cocoa 1973, coffee 1994, cotton 2010). We also find that explosive periods did not become more common or last longer in the second half of the sample period and that the most recent bubble episodes may not have been as severe as in mid-1970s.
Free boundary problems arising in the freezing of soils in a bounded region. III. Hydrodynamics of the unfrozen phase. IV. Thermal stresses in the frozen phase

Abstract In this paper, the method of characteristics is utilized to construct unique solutions to Problems II and III stated in Part I, and we demonstrate the continuous dependence of these solutions on the respective initial and boundary data. Moreover, asymptotic estimates for the critical time of breakdown in these solutions are also obtained.
Modeling Anisotropic Stress-Strain Response and Crystallographic Texture Evolution in α-Titanium during Large Plastic Deformation using Taylor-Type Models: Influence of Initial Texture and Purity

The anisotropic strain-hardening behavior and texture evolution during large plastic strains were investigated in two different grades of α-titanium. A recently proposed Taylor-type crystal-plasticity model[1] was used to predict the crystallographic texture evolution and anisotropic stress-strain response of these materials during large plastic strains at ambient temperature. The reasonable agreement between the predictions and the measurements reported here demonstrates the potential of these models for a class of titanium alloys in which plastic deformation is accommodated by both crystallographic slip and deformation twinning. The results of this study also provided quantitative insights into the effects of purity level on the slip and twin-hardening parameters, which are also observed to be relatively insensitive to the initial texture in the sample.
Exploration life support technology challenges for the Crew Exploration Vehicle and future human missions

As NASA implements the U.S. Space Exploration Policy, life support systems must be provided for an expanding sequence of exploration missions. NASA has implemented effective life support for Apollo, the Space Shuttle, and the International Space Station (ISS) and continues to develop advanced systems. This paper provides an overview of life support requirements, previously implemented systems, and new technologies being developed by the Exploration Life Support Project for the Orion Crew Exploration Vehicle (CEV) and Lunar Outpost and future Mars missions. The two contrasting practical approaches to providing space life support are (1) open loop direct supply of atmosphere, water, and food, and (2) physicochemical regeneration of air and water with direct supply of food. Open loop direct supply of air and water is cost effective for short missions, but recycling oxygen and water saves costly launch mass on longer missions. Because of the short CEV mission durations, the CEV life support system will be open loop as in Apollo and Space Shuttle. New life support technologies for CEV that address identified shortcomings of existing systems are discussed. Because both ISS and Lunar Outpost have a planned 10-year operational life, the Lunar Outpost life support system should be regenerative like that for ISS and it could utilize technologies similar to ISS. The Lunar Outpost life support system, however, should be extensively redesigned to reduce mass, power, and volume, to improve reliability and incorporate lessons learned, and to take advantage of technology advances over the last 20 years. The Lunar Outpost design could also take advantage of partial gravity and lunar resources.
The development and application of an image analyzing and processing system

This paper summarizes the development of an image analyzing and processing systems which is designed to determine particle size and particle size distribution of materials that have been transported atmospherically and hydrologically. The system, consisting of a redesigned microscope, a standard television camera, a Micro Works DS-65 DIGISECTOR video digitizer, and a TRS-80 computer, was constructed. The modified DS-65 was built as a peripheral device which converts the analog signal of the television camera to a digital signal and transfers the data through software control to the TRS-80. A machine language program was written to control the digitization and transfer of data. A BASIC language program, SCAN, automatically determines the particle size and particle size distribution. A new portion of the sample can be analyzed by adjusting two micrometers attached to the stage of the microscope. These micrometer adjusting screws allow accurate movement of the sample within a horizontal plane. The results of consecutive scans are accumulated and the distribution is plotted as a bar graph. Representative particle diameters, limited by microscope resolution, are on the order of 10 microns or greater in magnitude. Samples of particulates were tested and the results will be presented at the ACM Regional Meeting in Knoxville, Tennessee on April 1-3, 1982.
Large-scale exploratory analysis, cleaning, and modeling for event detection in real-world power systems data

In this paper, we present an approach to large-scale data analysis, Divide and Recombine (D&R), and describe a hardware and software implementation that supports this approach. We then illustrate the use of D&R on large-scale power systems sensor data to perform initial exploration, discover multiple data integrity issues, build and validate algorithms to filter bad data, and construct statistical event detection algorithms. This paper also reports on experiences using a non-traditional Hadoop distributed computing setup on top of a HPC computing cluster.
The Adopted Child Syndrome: A Methodological Perspective:

The term adopted child syndrome has repeatedly surfaced to explain behaviors in adopted children that seem rather uniquely related to their adoptive status. Specifically, these include problems in ...
Comparison results for the lower tail of Gaussian seminorms

Let ξ=(ξ n ) be i.i.d.N(0, 1) random variables andq(x), q′(x):R ∞→[0, ∞) be seminorms. We investigate necessary and sufficient conditions that the ratio ofP(q(ξ)<e) andP(q′(ξ)<e) goes to a positive constant as e→0+. We give satisfactory answers forl 2-norms and also some results for sup-norms andl p-norms. Some applications are given to the rate of escape of infinite dimensional Brownian motion, and we give the lower tail of the Ornstein-Uhlenbeck process and a weighted Brownian bridge under theL 2-norms.
The association between aerobic fitness and language processing in children: implications for academic achievement.

Event-related brain potentials (ERPs) have been instrumental for discerning the relationship between children’s aerobic fitness and aspects of cognition, yet language processing remains unexplored. ERPs linked to the processing of semantic information (the N400) and the analysis of language structure (the P600) were recorded from higher and lower aerobically fit children as they read normal sentences and those containing semantic or syntactic violations. Results revealed that higher fit children exhibited greater N400 amplitude and shorter latency across all sentence types, and a larger P600 effect for syntactic violations. Such findings suggest that higher fitness may be associated with a richer network of words and their meanings, and a greater ability to detect and/or repair syntactic errors. The current findings extend previous ERP research explicating the cognitive benefits associated with greater aerobic fitness in children and may have important implications for learning and academic performance.
Both the Dimerization and Immunochemical Properties of E-Cadherin EC1 Domain Depend on Trp156 Residue

Using site-directed mutagenesis, we show in this paper that the adhesive interface detected in cadherin crystals is unlikely to mediate adhesive interaction between myc- and flag-tagged E-cadherin molecules in human A-431 cells. We also found that a critical residue within this interface, His(233), is part of the epitope for mAb SHE78-7. This epitope was accessible to the antibody in the adhesive E-cadherin dimers, which is consistent with uninvolvement of the site containing His(233) in cell-cell adhesion. However, both the adhesive dimerization and the integrity of the SHE78-7 epitope depended on the same intramolecular interaction between Trp(156) and its hydrophobic pocket. Our data suggest that this interaction may have an important regulatory function in controlling the surface topology of the NH(2)-terminal domain of E-cadherin.
Charge-Coupled Device Spectra of Asteroids. I. Near-Earth and 3:1 Resonance Asteroids

Main-belt asteroids and cometary nuclei are both frequently suggested sources of the relatively short-lived near-earth asteroids (NEAs). The asteroidal origin hypothesis is studied by obtaining new high-quality reflectivity spectra of 19 NEAs and 23 asteroids near the 3:1 resonance, and by performing a systematic comparison of these two groups of spectra. Nonparametric statistical tests are used to check for consistency between the color distributions of the two populations. The tests indicate that the difference between the two distributions is generally not significant at the 3 sigma level. However, this conclusion is dependent on the (unknown) size distribution of the NEAs. The observations are compatible with the hypothesis that the NEAs are derived from the 3:1 resonance region, but do not imply that this is the only possible source region.
ANOTHER LOOK AT HOUSING ALLOWANCES: A RESPONSE TO CHESTER HARTMAN

Program experience with the Section 8 Existing Housing program and final research findings from the Experimental Housing Allowance Program have shown that, contrary lo Chester Hartman's conclusions in his recent Journal article, housing allowance programs similar to HUD's proposed Housing Payment Certificate program are an effective way to provide housing subsidies for families in need of assistance. Comparisons with public housing and unrestricted cash grants show that allowances produce the largest increase in housing consumption per subsidy dollar, and the design of the Housing Payment Certificate program will assure that those subsidies go to families most in need. Criticisms suggesting an inadequate supply of affordable, standard housing are refuted by the Section 8 Existing record of 750,000 families now renting units on the private market. Finally, discrimination has not prevented these families from finding standard housing or moving to different neighborhoods. The Housing Payment Certificate program is proposed not as a substitute for the Department's current commitment to a range of housing programs, but rather as the vehicle for new assistance.
Structure of Carboxyl Groups in Humic Acids

IN a recent communication1 we reported that four moles of water were evolved to one mole of carbon dioxide when humic acids, derived from a North Dakota lignite, were decarboxylated at 150° in a stream of dry nitrogen. It was suggested that some of the acid function of the humic acids was in the ionized form, —COO−H3O+·3H2O, although it was noted that relatively weak solid acids were not expected to be readily ionized. At the time the original experiments were carried out, infrared spectra of potassium bromide pellets of the resultant humic acids which had been dehydrated and decarboxylated at 150° for 65 h were recorded on a Beckman IR-5 spectrophotometer. It is the purpose of this communication to compare the original spectra with those reported in the preceding communication by Falk and Smith.
Singular value decomposition in adaptive beamforming

Karhunen-Loeve (K-L) expansions are fundamental to analysis of optimum array processors. It is shown how vector K-L expansion can be obtained by a generalized Fourier transform of the array output vector and an eigenvalue decomposition. In actual implementation of adaptive array processor singular value decomposition (SVD) of a matrix formed from transformed data is used instead of eigenvalue decomposition. It is also shown how K-L orthonormal system can be calculated from another orthonormal system by an eigenvector transformation that diagonalizes the covariance matrix of the original orthonormal expansion coefficients. Thus we have a computationally viable method for construction K-L orthonormal systems.
Yablo's paradox and kindred infinite liars

This is a defense and extension of Stephen Yablo's claim that self-reference is completely inessential to the liar paradox. An infinite sequence of sentences of the form "None of these subsequent sentences are true" generates the same instability in assigning truth values. I argue Yablo's technique of substituting infinity for self-reference applies to all so-called "self-referential" paradoxes. A representative sample is provided which includes counterparts of the preface paradox, Pseudo-Scotus's validity paradox, the Knower, and other enigmas of the genre. I rebut objections that Yablo's paradox is not a genuine liar by constructing a sequence of liars that blend into Yablo's paradox. I rebut objections that Yablo's liar has hidden self-reference with a distinction between attributive and referential self-reference and appeals to Gregory Chaitin's algorithmic information theory. The paper concludes with comments on the mystique of self-reference.
Investigation of phase-sensitive image amplification with elliptical Gaussian pump

We numerically analyze phase-sensitive parametric amplification of a multi-pixel text image and demonstrate that ∼10-dB gain is achievable with ∼10-kW total pump peak power, which makes it compatible with compact pump sources.
Electrical activity of the olfactory system.

Abstract Data have been presented concerning the relationship of nasal air flow to electrical activity in the olfactory system. The close correspondence between the Ottoson slow potential from the bulb and respiratory activity suggests that this slow potential is an excellent measure of respiration. The bursting activity at approximately 40 c/sec in the olfactory bulb appeared to be closely related with the rate and amplitude of the slow potentials, indicating that the slow potential was necessary for the elicitation of the 40 c/sec activity. Similar 40 c/sec activity in the basolateral amygdala was found to occur only at times when this activity was evident in the bulb, but did not occur invariably when 40 c/sec bulb activity was seen. In the shift from sleep to arousal, it was seen that the 40 c/sec activity in the bulb and amygdala did not occur until the first inspiratory cycle. Sniffing associated with active olfactory exploration was evident in the slow potential recordings and was associated with greatly increased 40 c/sec activity in both the bulb and amygdala.
Digital Modeling and PID Controller Design for MIMO Analog Systems with Multiple Delays in States, Inputs and Outputs

This paper presents a discrete-time state-space methodology for the digital modeling and design of an optimal digital proportional-integral-derivative (PID) plus state-feedback controller for multiple-input, multiple-output (MIMO) continuous-time systems with multiple time delays in states, inputs and outputs. To implement the digital design, first the Chebyshev quadrature formula together with a linear interpolation method is employed to obtain an extended discrete-time state-space model from the continuous-time multiple time-delay system. Then, a partially predetermined digital PID controller and the extended discrete-time state-space model are formulated as an augmented discrete-time state-space system utilizing state-feedforward and state-feedback linear-quadratic regulator (LQR) design. As a result, the parameters of the optimal PID controller and its associated state-feedback controller can be determined by tuning the weighting matrices in the LQR performance criteria. Further, an optimal discrete-time observer is jointly constructed for the multivariable system with multiple delays in states, inputs and outputs. The proposed design methodology can be applied to general MIMO continuous-time multiple time-delay systems for performance improvement and disturbance rejection. An illustrative example is given to demonstrate the effectiveness of the developed method.
Listener: A tool for client-side investigation of hypermedia navigation behavior

Behavioral researchers have employed hypermedia-based software applications in their experiments for some time. More recently, interest in the World-Wide Web has developed among researchers in the social sciences, and popular use of this new medium continues to grow at an incredible rate. This paper describes Listener, a tool developed to log users’ hypermedia and World-Wide Web navigation behavior using Apple Macintosh computers in a laboratory setting. Listener is able to capture navigation actions through cached documents, overcoming some of the problems associated with analyzing standard web server logs.
A possible explanation of low frequency shadows beneath gas reservoirs

Summary Asymptotic analysis of poroelastic Biot’s model for wave propagation in highly interbedded gas reservoirs suggests significant and anomalous amount of mode conversions between Fast and Slow P-waves, which may be observed from surface seismic reflection data. Those converted Pwaves experience high frequency dependent attenuation. In case if some converted wave propagated only a short fraction of its travel path as Slow P-wave it will not be attenuated as much as Slow P-wave, but it will be somewhat delayed relative to Fast P-wave reflection. The goal of this study is to estimate the influence of those converted waves into total reflected P-waves energy at low seismic frequencies.
Solid micromechanical valves fabricated with in situ UV-LIGA assembled nickel

Abstract In situ UV-LIGA assembled robust microcheck valves with large flow rates (>10 ml/s, displacement related), high-pressure support ability (>10 MPa) and high operational frequencies (>10 kHz) made of nano-structured nickel were presented in this paper. The microvalve consists of an array of 80 single microvalves to achieve the required flow rates. A novel in situ UV-LIGA process was developed for the fabrication. Test results show that the forward flow rate is about 19 ml/s under pressure of 90 psi. The backward flow rate is negligible. The loading/unloading test results show that the flow rates were repeated very well over a large range of tested pressure differences. The reliability of the valve is ensured by the low stress valve design and the robust nano-structured nickel material fabricated.
Historical forms of user production

Common conceptions of user production overstate its novelty while understating its variety. To respond to these lacks, this article develops an analytic map that enables a more nuanced historical and critical understanding and investigation of user production. Historical approaches are well suited for capturing the multifarious forms of user production while also avoiding the problem of a-historicism. The article develops a contextual typology of user production by theorizing it as a cultural form. Primary forms discussed include those of buyer; source, subject, interviewee; contestant; supplier; financier; inventor; activist; and member, all of which are related to their generative formations and conditions. The article concludes by suggesting the kinds of questions and studies that such a framework makes possible.
Mean winds and tidal and planetary wave motions over Hawaii during airborne lidar and observations of Hawaiian Airglow ALOHA-93

The mean and low-frequency wave motions in the mesosphere and lower thermosphere from 70 to 98 km were observed with the MF radar on Kauai during the Airborne Lidar and Observations of Hawaiian Airglow ALOHA-93 measurement campaign. Two-day mean zonal winds exhibited a transition from a variable structure with altitude at the beginning of October having westward motions near 80 km and eastward motions at upper and lower levels to more uniform eastward winds with altitude at the end of October. Two-day mean meridional motions were equally variable, with northward motions at all altitudes on October 1, northward motions above ∼80 km and southward motions below throughout much of the campaign, and largely northward motions at the end of October. Zonal and meridional winds exhibited significant oscillations at ∼5 to 30 day periods, indicative of planetary wave activity during this interval. Diurnal tidal amplitudes and phases were likewise variable, with maximum and minimum rms amplitudes of ∼ 35 and 10 ms−1, approximate phase quadrature with meridional leading zonal, amplitude and phase variability on time scales of ∼ 5 to 15 days, and an overall phase advance during October of ∼10 h. Other tidal components and the two-day wave had rms amplitudes of ∼ 5 to 10 ms−1.
Biphasic effect of estrogen on the sensitivity of the pituitary to luteinizing hormone-releasing factor (LRF).

Infusions of synthetic LRF were given in ovariectomized animals, and the effect on plasma concentrations of FSH and LH was determined by radioimmunoassay. Synthetic LRF induced a graded release of LH between doses of 100-2500 ng⁄hr and of FSH with doses of 100 and 500 ng⁄hr of the decapeptide. Peak concentrations were reached at 2 hr in the case of LH and 3 hr in the case of FSH. The relative magnitude of the release of LH was much greater than the magnitude of FSH release. Intravenous injection of 100 ng of estradiol benzoate partially blocked the LH and FSH response to LRF within 1 hr following injection. The inhibitory effect was maximal at 2 hr and had largely disappeared by 4 hr. Injections of 50 or 200 ng of progesterone iv did not modify the responses to LRF infusion. If the infusion of LRF was delayed until 6 hr after the injection of estradiol benzoate, the pattern changed, and there was an enhanced response to LRF, such that plasma LH concentrations were 2½-fold greater in estradiol-treated anim...
Odd frequency pairing in superconductors

The properties of a superconductor having an energy gap function Δk(ω n ) which is an odd function of frequencyω n, or time, are investigated. One finds (a) the allowed pair orbital angular momenta for spin zero and spin one are interchanged, permittingS= 0, l=1 and S=1, l=0 condensates; (b) there exists an equal-time order parameter corresponding to condensation of a spin wave coupled to two fermions, in contrast to the conventional timereversed fermion pair condensate; an explicit energy gap equation is derived for this composite operator condensate; (c) the coherence factors are shown to be reversed from those of conventional pairing, forω>2Δ, removing the peak in thea+C conductivityσ(ω) and generating a peak in theω>2Δ acoustic attenuation as a function of temperature; (d) the Josephson current vanishes between an even and odd frequency superconductor, and vanishes to leading order in the tunneling rates ∼t 12 2 .
The Second Spectrum of Silicon

New observations of the spectrum Si II from λ 700 to λ 9500 are described, 300 lines being listed in addition to those previously assigned to this spectrum. The analysis includes details of the perturbations of the 3 s 2 nx 2 X series up to x = g . Structures of type 3 s 3 p ( 3 P ) nx up to x = f have been identified and many peculiarities found. A large proportion of the levels show auto-ionization effects, even up to a term at 25000 cm -1 above ionization. The same term also shows an anomalous degree of excitation in the hollow cathode for two levels which cannot auto-ionize.
Training the “Wizards”: A Model for Building Self Efficacy and Peer Networks Among Urban Youth Workers

This article presents a community's efforts to address the professional development needs of frontline youth workers. A coalition designed a 13-week Youth Worker Training Institute to increase youth workers' knowledge, skills, self-efficacy, and professional networks. After the Institute, participants reported feeling more skillful, connected to other youth workers, confident, professional, reflective, and being more powerful change agents. Based on results from this formative evaluation, we suggest that it was multiple teaching and learning strategies that promoted reflection, peer learning, and networking—that contributed to youth workers gaining knowledge and skills that in turn increased their confidence and sense of self-efficacy.
Using the Concept of Information to Optimally Design Experiments With Uncertain Parameters

When thermal systems are described by models, it is necessary to know the properties and parameters of the model to ensure accurate results. These properties are usually determined from experiments designed to maximize the precision of the estimated properties. Achieving such high precision requires that all of the other properties be known with certainty. We describe a method of design and estimation based upon Fisher's concept of information that achieves good precision in estimating thermal properties even when the other parameters are known only approximately
On torsion of thin cylindrical shells

Abstract I n the following we consider an application of the theory of elastic, thin, cylindrical shells to the problem of St. Venant torsion. We obtain in this way simple explicit general results for non-homogeneous shells, which include as special case Bredt's formulas for closed tubes and known results for tubes slit along a generator. We also find that the problem of St. Venant torsion requires use of a formulation of shell theory which is more accurate than Love's first approximation theory.
Density functional theory study of small nickel clusters.

The stable geometries and atomization energies for the clusters Ni n (n = 2–5) are predicted with all-electron density functional theory (DFT), using the BMK hybrid functional and a Gaussian basis set. Possible isomers and several spin states of these nickel clusters are considered systematically. The ground spin state and the lowest energy isomers are identified for each cluster size. The results are compared to available experimental and other theoretical data. The molecular orbitals of the largest cluster are plotted for all spin states. The relative stabilities of these states are interpreted in terms of superatom orbitals and no-pair bonding.