cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of a new rifamycin derivative, rifalazil, on liver microsomal enzyme induction in rat and dog

1. The effect of a new rifamycin derivative, rifalazil (KRM-1648), on liver microsomal enzyme induction was studied in rat and dog with repeated oral administration of the compound. Relative liver weight, cytochrome b5 and P450 contents, enzyme activities of NADPH-cytochrome c reductase, aniline hydroxylase, ρ-nitroanisole O-demethylase, aminopyrine N-demethylase, and erythromycin N-demethylase were measured. 2. In rat, rifalazil treatment at 300 mg/kg/day for 10 days increased cytochrome b5 content but it did not affect liver weight, P450 content or enzyme activities. In contrast, rifampicin and rifabutin increased relative liver weights, cytochrome contents and enzyme activities under similar conditions. 3. In dog, rifalazil did not affect any parameters at 30 or 300 mg/kg/day for 13 weeks. 4. These findings indicate that rifalazil is not an enzyme inducer in rat and dog. This property differs from other rifamycin derivatives such as rifampicin and rifabutin.
Fundamental limitations in microelectronics—I. MOS technology

The physical phenomena which will ultimately limit MOS circuit miniaturization are considered. It is found that the minimum MOS transistor size is determined by gate oxide breakdown and drain-source punch-through. Other factors which limit device size are drain-substrate breakdown, drain ‘corner’ breakdown and substrate doping fluctuations. However these limitations are less severe than the oxide breakdown limitation mentioned above. Power dissipation and metal migration limit the frequency and/or packing density of fully dynamic and of complementary MOS circuits. In static non-complementary circuits, power dissipation is the principal limitation of the number of circuit functions per chip. The channel length of a minimum size MOS transistor is a factor of 10 smaller than that of the smallest present day devices. The tolerances required to manufacture such a transistor are compatible with electron beam masking techniques. It is thus possible to envision fully dynamic silicon chips with up to 10^7–10^8 MOS transistors per cm^2.
Graphics Processing Unit-Based Ultrahigh Speed Real-Time Fourier Domain Optical Coherence Tomography

This paper describes a series of novel graphics processing unit (GPU)-based image reconstruction and visualization methods that we developed for realizing ultrahigh speed, real-time Fourier domain optical coherence tomography (FD-OCT). Several GPU-based algorithms including high-speed linear/cubic interpolation, gridding-based nonuniform fast Fourier transform (NUFFT), numerical dispersion compensation, and multi-GPU implementation were developed to improve the point-spread function, SNR roll-off, and stability of the system. Full-range complex-conjugate-free FD-OCT was also implemented on the GPU architecture to double the imaging range and to improve the SNR. The maximum processing speed of $>$ 3 Gigavoxels/s ( $>$ 6 Mega-A-scans/s of 1024-pixel FD-OCT) was achieved using the latest GPU module from NVIDIA. The GPU-based volume rendering enabled real-time four-dimensional (4-D), i.e., 3-D + time, FD-OCT imaging, and a 5 volume/s 4-D FD-OCT system was demonstrated via in vivo tissue imaging. These GPU technologies were highly effective in circumventing the well-known imaging reconstruction and visualization bottlenecks existing among current ultrahigh speed FD-OCT systems and could open the door to realize interventional OCT imaging for applications in guiding microsurgery.
CORRELATIONS BETWEEN THE WAIS AND REVISED BETA, WECHSLER MEMORY SCALE AND QUICK TEST IN A VOCATIONAL REHABILITATION CENTER

A correlational analysis of the Revised Beta, the Wechsler Memory Scale, and the Ammons' Quick Test (Forms 1, 2, 3) with 30 clients from a vocational rehabilitation center yielded correlations with the WAIS of .83, .80, and .84 respectively. For a retarded subgroup of 16 Ss only the Wechsler Memory Scale was significantly correlated with WAIS IQ (R = .61). The Revised Beta correlation of .37 suggested this test may be less reliable when used with mentally retarded Ss.
New Roundabouts Send Axons into the Fas Lane

The functional comparison of each robo gene raises some fascinating questions about the different ways that an axon can interpret the Slit signal. Robo seems to specialize in the short-range response. Robo2, which mediates responses at greater distance, is not functionally interchangeable with Robo. While this could represent subtle differences in the pattern and/or regulation of their expression, there is another likely source of distinction. Despite overall structural conservation among Robos, there are intriguing differences. For example, Robo contains four conserved intracellular peptide motifs thought to recruit signaling proteins such as the Abl tyrosine kinase and its substrate Enabled to convey and/or regulate the repellent signal (Bashaw et al. 2000xBashaw, G.J., Kidd, T., Murray, D., Pawson, T., and Goodman, C.S. Cell. 2000; 101: 703–715Abstract | Full Text | Full Text PDF | PubMedSee all ReferencesBashaw et al. 2000). However, only two of these motifs are present in Robos 2 and 3 (Figure 1BFigure 1B). Since Robos 2 and 3 are fully functional repellent receptors, these missing sites appear to play more subtle roles in the process, as suggested by the mild midline phenotype of enabled mutants. While the downstream differences may distinguish long-range and short-range repulsion, additional signaling proteins are likely to mediate these functions. Ultimately, making the link between signals at the cell surface and the motility machinery inside of the cell will help us understand how axonal growth cones make up their minds. But these answers lie just beyond the horizon.*To whom correspondence should be addressed (e-mail: davie@hms.harvard.edu).
Potential value of antioxidant-rich foods in slowing age-related macular degeneration.

JAMA Dietary Intake of Antioxidants and Risk of Age-Related Macular Degeneration Context: Age-related macular degeneration (AMD) is the most prevalent cause of irreversible blindness in developed countries. Recently, high-dose supplementation with beta carotene, vitamins C and E, and zinc was shown to slow the progression of AMD. Objective: To investigate whether regular dietary intake of antioxidants is associated with a lower risk of incident AMD. Design: Dietary intake was assessed at baseline in the Rotterdam Study (1990-1993) using a semiquantitative food frequency questionnaire. Incident AMD until final follow-up in 2004 was determined by grading fundus color transparencies in a masked way according to the International Classification and Grading System. Setting: Population-based cohort of all inhabitants aged 55 years or older in a middle-class suburb of Rotterdam, the Netherlands. Participants: Of 5836 persons at risk of AMD at baseline, 4765 had reliable dietary data and 4170 participated in the follow-up. Main Outcome Measure: Incident AMD, defined as soft distinct drusen with pigment alterations, indistinct or reticular drusen, geographic atrophy, or choroidal neovascularization. Results: Incident AMD occurred in 560 participants after a mean follow-up of 8.0 years (range, 0.3-13.9 years). Dietary intake of both vitamin E and zinc was inversely associated with incident AMD. The hazard ratio (HR) per standard deviation increase of intake for vitamin E was 0.92 (95% confidence interval [CI], 0.84-1.00) and for zinc was 0.91 (95% CI, 0.83-0.98). An above-median intake of all 4 nutrients, beta carotene, vitamin C, vitamin E, and zinc, was associated with a 35% reduced risk (HR, 0.65; 95% CI, 0.46-0.92) of AMD. Exclusion of supplement users did not affect the results. Conclusion: In this study, a high dietary intake of beta carotene, vitamins C and E, and zinc was associated with a substantially reduced risk of AMD in elderly persons.
CXCR4 expression in neuroblastoma primary tumors is associated with clinical presentation of bone and bone marrow metastases

Abstract Background/Purpose The chemokine receptor, CXCR4, has been implicated in the mechanism of tumor cell metastasis to bone and bone marrow. Neuroblastoma, a cancer of children, is well known for its potential to metastasize to these sites. The goal of this study was to investigate whether the degree of expression of CXCR4 on cells from neuroblastoma primary tumors was related to the pattern of metastatic involvement. Methods Archived neuroblastoma primary tumor samples and clinical data were collected from 26 patients with newly diagnosed neuroblastoma. Expression of CXCR4 (12g5 antibody) was evaluated on formalin-fixed paraffin-embedded tumor tissues using standard immunohistochemical techniques. Each tumor was graded (grade 1 through 4) based on the proportion of cells that were positive for the 12g5 antibody. Tumor grades for CXCR4 expression were compared with clinical data from each patient. Results Higher grades of expression (grade 3 and 4) were found in tumors from patients with high-stage disease ( P P ≤ .01). Clinical outcome in patients with tumors highly expressing CXCR4 was significantly worse ( P Conclusions CXCR4 expression in neuroblastoma primary tumors is significantly correlated with the pattern of metastatic spread.
Charge Dividing Mechanism on Resistive Electrode in Position-Sensitive Detectors

A complete charge-division mechanism, including both the diffusion and the electromagnetic wave propagation on resistive electrodes, is presented. The charge injected into such a transmission line divides between the two ends according to the ratio of resistancies and independently of the value of the line resistance, of the propagation mechanism and of the distribution of inductance and capacitance along the line. The shortest charge division time is achieved for Rl, = 2? (L/C)?, where R, L, C are resistance, inductance and capacitance per unit length and l is the length of the line.
Spatiotemporal relation between gap junctions and fascia adherens junctions during postnatal development of human ventricular myocardium

BACKGROUNDThe growing postnatal human heart maintains electromechanical function while undergoing substantial changes of cellular topology and myocardial architecture. The capacity for growth and remodeling of ventricular myocardium in adaptation to the hemodynamic changes of early infancy later declines. This decline is associated with changes in electromechanical properties of the myocardium, which suggest that the electrical and mechanical interactions between the myocytes may change in an age-dependent manner. Thus, reduction in the capacity for myocardial growth and adaptability may relate to age-dependent alterations in the patterns of the intercellular junctions that mediate electrical and mechanical coupling. We therefore examined the hypotheses that (1) age-dependent changes in the distribution patterns of gap junctions and fasciae adherentes, the intercellular junctions responsible, respectively, for electrical and mechanical coupling, accompany postnatal development in the human heart and that ...
State and local response to damaging land subsidence in United States urban areas

Abstract Land subsidence caused by man-induced depressuring of underground reservoirs has occurred in at least nine urban areas in the United States. Significant efforts to control it have been made in three areas: Long Beach, California; Houston-Galveston, Texas; and Santa Clara Valley, California. In these areas coastal flooding and its control cost more than $300 million. Institutional changes were required in each area to ameliorate its subsidence problem. In Long Beach and Houston-Galveston, efforts were made to mitigate subsidence only after significant flood damage had occurred. To arrest subsidence at Long Beach, the city lobbied for a special state law, the California Subsidence Act, that required unitization and repressuring of the Wilmington oil field. In the Houston-Galveston region, the Texas State Legislature authorized formation of the Harris-Galveston Coastal Subsidence District with authority to regulate ground-water pumping by permit. This solution, which was achieved through efforts of entities affected by subsidence, was the product of a series of compromises necessitated by political fragmentation and disjointed water planning in the region. Amelioration of subsidence in the Santa Clara Valley was a collateral benefit from the effort by water users to curtail ground-water overdraft in the valley. Importation of surface water and a tax on ground-water pumpage reduced ground-water use, thereby allowing the recovery of water level and the arresting of subsidence.
Two years later: effects of question repetition and retention interval on the eyewitness testimony of children and adults

This study examined witnesses' memories for an event experienced 2 years earlier. Ss in 4 age groups (6-, 8- and 10-year-olds and adults; N= 79) answered repeated questions about an ambiguous incident that occurred as part of an earlier study (D. A. Poole & L. T. White, 1991). Surprisingly, the effects of question repetition were similar to the patterns observed 2 years ago. There were important differences in the testimonies of children and adults, however, that were not observed in the initial study: Children were less consistent than adults across sessions on yes-no questions, less accurate in response to open-ended questions, and more likely to fabricate answers to a question about a man's occupation. Some children also confused the actions of 2 research assistants. These results indicate the need for additional research on qualitative and quantitative changes in children's testimonies over long delays. The literature on children's eyewitness testimony is a story of contradictions, with developmental trends in accuracy, suggestibility, and response to stress differing from study to study (see Ceci & Bruck, 1993, for a review). Discrepancies have prompted critics to argue that eyewitness research lacks theoretical cohesion and that "established theories of perception and memory are not immediately applicable" because of the influence of motivational and social factors in event reporting (Sheehy & Chapman, 1982, p. 345). In early studies, concerns about ecological validity often loomed larger than efforts to reconcile eyewitness findings with traditional concepts of memory development.
An impedance study of the silicon—solution interface under illumination

Abstract Surface states at the semiconductor—electrolyte interface under illumination have been determined. The Faradaic reaction involved at the interface is the hydrogen evolution. An equivalent circuit is proposed which is chosen as giving the best fit to the impedance data among six possible arrangements consistent with present models of the interface. Surface states act as recombination centers decreasing the Faradaic efficiency for the hydrogen evolution reaction. Surface state density at a given bias potential has been calculated to be ≈ 10 12 cm −2 . Adsorbed ions induce surface states. Helmholtz double layer resistance is larger than the space charge resistance in the Tafel region; hence, the rate determining step for hydrogen evolution on Si lies in the double layer region.
Getting RNA and Protein in Phase

Nonmembrane-bound organelles such as RNA granules behave like dynamic droplets, but the molecular details of their assembly are poorly understood. Several recent papers identify structural features that drive granule assembly, shedding light on how phase transitions functionally organize the cell and may lead to pathological protein aggregation.
The young SMC cluster NGC 330

A color-magnitude diagram has been obtained for the young SMC cluster NGC 330. The diagram shows a well-defined main sequence, a group of blue supergiants, a group of red supergiants between B-V = 1.2 m and 1.6 m about one magnitude fainter, and an empty Hertzsprung gap. The surrounding field is a composite of a very gold population resembling galactic globular clusters and a very young population. DDO and infrared photometry strongly suggest that the cluster is metal-poor, but a definitive measure could not be made because of calibration difficulties. The cluster's age is estimated at 12 million years, with the surrounding field about 50 percent older. The cluster will prove very useful in testing stellar evolution models for young, metal-poor stars if the cluster's metallicity can be established via high-resolution spectroscopy.
Secondary structure of proteins associated in thin films

The solid state secondary structure of myoglobin, RNase A, concanavalin A (Con A), poly(L-lysine), and two linear heterooligomeric peptides were examined by both far-uv CD spectroscopy1 and by ir spectroscopy. The proteins associated from water solution on glass and mica surfaces into noncrystalline, amorphous films, as judged by transmission electron microscopy of carbon-platinum replicas of surface and cross-fractured layer. The association into the solid state induced insignificant changes in the amide CD spectra of all alpha-helical myoglobin, decreased the molar ellipticity of the alpha/beta RNase A, and increased the molar ellipticity of all-beta Con A with no change in the positions of the bands' maxima. High-temperature exposure of the films induced permanent changes in the conformation of all proteins, resulting in less alpha-helix and more beta-sheet structure. The results suggest that the protein alpha-helices are less stable in films and that the secondary structure may rearrange into beta-sheets at high temperature. Two heterooligomeric peptides and poly(L-lysine), all in solution at neutral pH with "random coil" conformation, formed films with variable degrees of their secondary structure in beta-sheets or beta-turns. The result corresponded to the protein-derived Chou-Fasman amino acid propensities, and depended on both temperature and solvent used. The ir and CD spectra correlations of the peptides in the solid state indicate that the CD spectrum of a "random" structure in films differs from random coil in solution. Formic acid treatment transformed the secondary structure of the protein and peptide films into a stable alpha-helix or beta-sheet conformations. The results indicate that the proteins aggregate into a noncrystalline, glass-like state with preserved secondary structure. The solid state secondary structure may undergo further irreversible transformations induced by heat or solvent.
Targeted Chemical Wedges Reveal the Role of Allosteric DNA Modulation in Protein−DNA Assembly

The cooperative assembly of multiprotein complexes results from allosteric modulations of DNA structure as well as direct intermolecular contacts between proteins. Such cooperative binding plays a critical role in imparting exquisite sequence specificity on the homeobox transcription factor (Hox) family of developmental transcription factors. A well-characterized example includes the interaction of Hox proteins with extradenticle (Exd), a highly conserved DNA binding transcription factor. Although direct interactions are important, the contribution of indirect interactions toward cooperative assembly of Hox and Exd remains unresolved. Here we use minor groove binding polyamides as structural wedges to induce perturbations at specific base steps within the Exd binding site. We find that allosteric modulation of DNA structure contributes nearly 1.5 kcal/mol to the binding of Exd to DNA, even in the absence of direct Hox contacts. In contrast to previous studies, the sequence-targeted chemical wedges reveal the role of DNA geometry in cooperative assembly of Hox-Exd complexes. Programmable polyamides may well serve as general probes to investigate the role of DNA modulation in the cooperative and highly specific assembly of other protein-DNA complexes.
In vitro interaction of zeolite fibers with individual cells (macrophages NR8383): measurement of intracellular oxidative burst

Inhalation of fibrous minerals such as asbestos and erionite can cause various lung diseases, including cancer. The mechanism by which these fibers induce disease is an area of active research. Interaction of fibers with lung macrophages leads to release of many substances. Among these, reactive oxygen metabolites (which include hydrogen peroxide, superoxide, and possibly hydroxyl radicals) are proposed to cause cellular damage. In this paper, we report a method for observing intracellular hydrogen peroxide release as rat lung-derived macrophages (NR-8383) phagocytize erionite fibers. This is possible by observing the fluorescence of 2',7'-dichlorofluorescein-the intracellular, oxidized form of 5 (and 6)-carboxy-2', 7'-dichlorodihydrofluorescin formed in the presence of newly released hydrogen peroxide. We are able to image the fluorescence within a single cell, thereby allowing us to get information on the spatial distribution of the metabolites.
The dispersion theory of the lamb shift

Abstract Dispersion theoretic perturbation techniques originally developed by Dashen and Frautschi for the discussion of electromagnetic corrections to the strong interactions are used in evaluating the Lamb shift in hydrogen-like atoms. We first indicate how to determine the Lamb shift to any order in the binding strength of the Coulomb potential (Zα) and the perturbation by the radiation field (α). All infrared divergences arising from the Coulomb potential are shown to cancel in a straightforward manner. All infrared divergences of the perturbation are handled in a dispersion theoretic manner. Explicit formulas are given for the lowest order, α(Zα)4me, Lamb shift for spin zero and spin one-half electrons. A real numerical evaluation of this shift is not possible because of divergences indicated in the text; however, some fairly simple numerical estimates are made which indicate that the formulas derived in the text give the cor ect sign and order of magnitude of the level shift. Defects and virtues of the dispersion perturbation formulae are discussed. A short appendix on the possible treatment of the hyperfine structure of hydrogen by the same techniques concludes the work.
Emergency medical services development in the Seychelles islands

The Republic of the Seychelles enjoys a sophisticated health care system by developing country standards. Basic food, water, sanitation, and preventative health care needs have been addressed and the Seychelles Ministry of Health has recently focused on the need to improve the country's emergency medical services (EMS). In response to this need, a joint international collaborative effort designed to improve the island's EMS was launched. This report profiles the current health care system in the Seychelles, with special emphasis on EMS. It also describes an international collaborative effort between the Seychelles Ministry of Health and the UCLA Center for International Emergency Medicine designed to improve existing EMS.
Space debris: Electrodynamic effects

It is shown that electrodynamic forces play a crucial role in the orbital dynamics of the small Al2O3 particles that are injected into the terrestrial magnetosphere during solid rocket propellant burns. Due to the simplified model that is used to describe the plasma distribution in the magnetosphere, the present results are necessarily preliminary. Even so, it appears that the smallest particles (a = 0.1 micron) will be rapidly eliminated from the magnetosphere. Evaluation of the fate of the somewhat larger (a = 1 micron) particles awaits the construction of a more complete and realistic model of the magnetospheric plasma.
Simulation of a photovoltaic emulator

This paper will outline the simulation of a photovoltaic emulator. A photovoltaic emulator is a DC-DC converter which has similar electrical characteristics to a photovoltaic panel. A photovoltaic emulator allows PV systems to be analyzed in a controlled environment where using actual photovoltaic panels would produce inconsistent results for the PV system, due to variability in outside temperature and weather conditions.
NUMERICAL SIMULATION OF TWO-DIMENSIONAL MELTING AND RESOLIDIFICATION OF A TWO-COMPONENT METAL POWDER LAYER IN SELECTIVE LASER SINTERING PROCESS

Selective laser sintering (SLS) of metal powder is an emerging technology by which metal parts can be fabricated in a layer by layer fashion. SLS of the first layer is modeled as melting and resolidification of a metal powder layer subject to a moving heat source on top, while the bottom is adiabatic. SLS of the consecutive layer is modeled as melting and resolidification of a metal powder layer on top of the existing multiple resolidified layers. The results indicate that the thicknesses of the loose metal powder layer, the moving heat source intensity, and the scanning velocity have significant effects on the sintering process in both the first layer and each subsequent layer. A parametric study is performed, and the best combination of processing parameters is recommended.
The Transracial Adoption Debate: Counseling and Legal Implications

Over the last 30 years, the practice of White American parents adopting African American children has been the focus of much deliberation and commentary. In this article, the authors illuminate relevant literature and research regarding transracial adoption. Counseling and legal implications are also discussed.
Fermionic Spin Excitations in Two- and Three-Dimensional Antiferromagnets

Spin excitations in an ordered Heisenberg magnet are magnons---bosons with spin 1. That may change when frustration and quantum fluctuations suppress the order and restore the spin-rotation symmetry. We show that spin excitations in the $S=1/2$ Heisenberg antiferromagnet on a kagome lattice are spinons---fermions with spin $1/2$. In the ground state the system can be described as a collection of small, heavy pairs of spinons with spin 0. A magnetic excitation of lowest energy amounts to breaking up a pair into two spinons at a cost of 0.06 J.
Collagens act as ligands to stimulate human monocytes to produce mononuclear cell factor (MCF) and prostaglandins (PGE2).

Abstract Blood mononuclear cells from patients with rheumatoid arthritis produce the lymphokine, leukocyte inhibitory factor (LIF) in response to collagens in vitro, and blood monocytes release prostaglandins (PGE 2 ) and a factor, mononuclear cell factor (MCF) which stimulates collagenase and PGE2 production by cultured synovial cells. We therefore examined the effect of collagens on the production of PGE 2 and MCF. Blood mononuclear cells from 6 patients with rheumatoid arthritis and 6 normal subjects were cultured in native human types I, II, or III collagen-coated tubes, or with streptokinase-streptodornase (SK-SD), and the supernatant media derived from these cultures analyzed for the presence of MCF, PGE 2 , and LIF. Types II and III collagens, as well as SK-SD, markedly stimulated MCF production by the cells from all 12 subjects (MCF activity, expressed as a mean stimulation index (SI) ± SEM, was 43 ± 12 for type II, 33 ± 7 for type III, and 37 ± 23 for SK-SD). Type I collagen was less stimulatory (mean SI 10 ± 7). Cells from the patients with rheumatoid arthritis, but not the normal subjects, produced LIF in response to types II or III collagens but not to type I collagen. PGE 2 production by blood mononuclear cells paralleled that of MCF, although abrogation of PGE2 release with indomethacin did not reduce MCF production. a chains purified from denatured collagens also stimulated MCF production. Using cells from patients with rheumatoid arthritis, type II collagen stimulated production of all three factors in the presence of polymyxin B or fibronectin-depleted serum, suggesting, respectively, that neither endotoxin nor fibronectin were responsible for their generation. Monocytes, purified from normal blood by an adherence tech
Cellular automata, ΩΩ-regular sets, and sofic systems

Abstract We study and compare several mechanisms for defining sets of biinfinite words (ωω-languages), namely ωω-finite automata, adherences of regular languages and sofic systems. We show that a sofic system is a topologically closed ωω-regular set. We also show that there is a one-to-one correspondence between sofic systems and the adherences of regular languages. We give a complete proof of the closure of the ωω-regular sets under ωω-rational relations and under Boolean operations. Finally, we disprove Hurd's conjecture [15] on bi-extensible subsets of languages, and show that the conjecture would hold if a different definition were used.
Molecularly sensitive optical ranging using nonlinear interferometric vibrational imaging

We explore combining Coherent anti-Stokes Raman Scattering with Optical Coherence Tomography ranging when low numerical aperture scanning is used, and demonstrate ranging of layers in a Raman-active medium.
Preference for the Outcome That Follows a Relatively Aversive Event: Contrast or Delay Reduction?

Pigeons prefer a positive discriminative (S+) stimulus that follows a less preferred event (a large number of required responses, a longer delay, or the absence of food) over a different S+ with a similar history of reinforcement that follows a more preferred event (a single required response, no delay, or food). We proposed that this phenomenon results from contrast (referred to as within-trial contrast) between the less preferred initial event and the signal for reinforcement. Delay reduction theory (Fantino, 1969) can account for these results by proposing that the less preferred initial event lengthens the duration of the trial, thereby allowing the S+ stimulus to occur later in the trial and thus become a better predictor of reinforcement. In the present experiments, we further explored this effect. In Experiment 1, we controlled for trial duration by using a fixed ratio response (30 pecks) as one initial event and the absence of pecking for the same duration as the other initial event (0 pecks). The pigeons showed a reliable preference for the positive stimulus that followed the least preferred initial event. In Experiment 2, we controlled for trial duration by using 30 pecks as one initial event and 1 peck followed by a delay that matched the duration of the preceding 30-peck trial. (Group Time Same). For Group Time Different, there was no delay following the 1-peck initial event. For Group Time Same, preference for the initial event negatively predicted the pigeons’ preference for the S+ stimulus that followed, supporting the contrast account. A somewhat greater preference for the discriminative stimulus that followed the least preferred initial event was found for Group Time Different suggesting that in addition to contrast, delay reduction also may play a small role. However, the greater initial-event preference found for Group Time Different suggests that contrast can account for the group difference as well.
Spectrum of density fluctuations in a particle-fluid system. I: Monodisperse spheres

Abstract This paper presents an extension of the analysis shown in Part I to a polydisperse particle-fluid system. The density autocorrelation is shown to be a function of two quantities, a generalized Overlap function for which an analytical expression is derived, and the radial distribution function (RDF). In Fourier transform space, the density spectrum again appears to be a strong function of the mean particle size, and secondarily the mean particle separation distance. One unusual result is previously observed oscillations in the density spectrum of a monodisperse system of particles are severely dampened or even eliminated in the polydisperse case, depending on the width of the particle size distribution. Apparently contributions from different particle correlations interfere with each other, thereby reducing the coherent oscillations seen in the monodisperse particle-fluid system. Furthermore at large wavenumbers, the spectrum decays with a −2 power-law, independent of the shape of the particle size distribution. This behavior can be traced to the Overlap function which controls the behavior of the spectrum beyond the first peak. Remarkably the −2 power-law spectrum is determined by the shape of the particles (i.e. spheres) rather than their spatial distribution (RDF). The effect of an asymptotically large pressure gradient on the correlation of several important higher-order moments is revisited for the polydisperse system. The relatively simple relationships developed for the monodisperse system are lost in the polydisperse case because particles of different sizes will be influenced differently by an applied pressure gradient. The result is moments that are of different order in velocity can no longer be related to each other (as they were in the monodisperse system), even in this idealized flow. A more comprehensive understanding of this phenomenon can only be achieved through direct numerical simulation or experiment.
Del periodismo al costumbrismo: La obra juvenil de Pereda

(1992). Del periodismo al costumbrismo: La obra juvenil de Pereda. Romance Quarterly: Vol. 39, Studies in Spanish Literature, 1750–1915, pp. 33-39.
N-Acetylneuraminic acid accumulation in a buoyant lysosomal fraction of cultured fibroblasts from patients with infantile generalized N-acetylneuraminic acid storage disease

Cultured fibroblasts from control individuals and two patients affected with the infantile variant of generalized N-acetylneuraminic acid (NeuAc) storage disease were disrupted by nitrogen cavitation, and the post-nuclear supernatant fractions were subjected to subcellular fractionation on Percoll gradients. Accumulating NeuAc in affected fibroblasts (approx. 150 nmol/mg protein) co-localized with the lysosomal marker N-acetyl-β-hexosaminidase (Hex), in a fraction with a mean density of 1.035 g/ml. In contrast, more than 70% of the Hex activity of control cells sedimented in comparable gradients with a density of more than 1.07 g/ml. The lysosomal localization of NeuAc accumulation in affected fibroblasts was confirmed by treatment of post-nuclear supernatant fractions with 0.5 mM Gly-Phe-β-naphthylamide (20 min, 37°C) prior to centrifugation, which resulted in the simultaneous loss of latency of Hex and free NeuAc, and their association with the soluble fraction on Percoll gradients. The results provide direct evidence for the accumulation of free NeuAc in a unique buoyant lysosomal fraction of affected fibroblasts.
Improving platform energy: chip area trade-off in near-threshold computing environment

Recent studies on near-threshold computing (NTC) investigated an optimum supply voltage which yields minimum energy per operation (Emin), and proposed various optimization techniques at the device, circuit, and architecture levels to further minimize Emin. However, most of these studies often overlooked the significance of (i) energy consumption of off-chip memory accesses; (ii) energy loss of voltage regulators (VRs); and (iii) the cost of chip area in NTC environment. In this paper, we first demonstrate the increasing significance of (i) and (ii) in NTC environment with a comprehensive set of device, circuit, and architectural-level models. Second, we explore technology optimization to improve the trade-off between platform energy and chip area considering (iii) in NTC environment. The experimental results show that our optimized technology achieves 4% to 21% energy reduction for various chip area constraints, achieving significant improvement in trade-off between platform energy and chip area for a wide range of parallel benchmarks.
L-amino-acid oxidase. I. Effect of pH.

Abstract The effect of pH on K m and upon the rate constants associated with the reduction of oxidized enzyme by substrate and with the oxidation of reduced enzyme has been examined for the case of purified l -amino-acid oxidase ( l -amino-acid:O 2 oxidoreductase (deaminating), EC I.4.3.2) of Eastern Diamondback Rattlesnake ( Crotalus Adamanteus ), using l -leucine as a substrate at 25°, 30° and 35°. The effect of pH on K m yields two p K 's: one in the range 5.7–5.9 corresponding to the enzyme-substrate ( ES ) intermediate and one in the range 8.2–8.4 corresponding to the free enzyme. The variation of the two sets of p K 's with temperature both yield an apparent enthalpy of ionization of 7.5 kcal/mole. These data lead to the conclusion that histidyl is most likely involved in the catalysis at the active center. The variation of the reduction rate constant k obs with pH parallels the variation of K m with pH, indicating that the variation of k obs with pH depends on the variation in the availability of ES intermediate with pH. The oxidation rate constant, k ox , does not vary appreciably with pH, suggesting that the oxidation process proceeds via a direct combination of oxygen and reduced form or forms of the enzyme without the mediation of catalytic groups which may be titrated in the range of pH studied.
Threat and group creativity

In this paper we briefly review the literature on group creativity under threat, present a perspective designed to suggest a single approach to a reconciliation of the conflicting findings, discuss interventions capable of enhancing group creativity under threat, and conclude with suggestions for future research. The authors are grateful to the San Jose State University Department of Organization and Management and College of Business for research support.
Design and characterization of a 12-channel dual-wavelength fiber-coupled laser system

A compact, ruggedized 12-channel, dual wavelength, fiber-coupled laser system was designed, assembled and tested to support fiber injection experiments. A flashlamp pumped, Q-switched, Nd:Cr:GSGG laser, operating at 1061 nm was assembled and characterized. To optimize the laser for fiber injection, a stable, multimode, Polarization Output Coupled (POC) resonator design was utilized. The design did not use any active cooling and was ideal for low duty cycle applications requiring no more than one shot every 30 seconds. The laser output was frequency doubled to 530 nm utilizing a Type II interaction in a KTP crystal. A nonlinear conversion efficiency of 56% was obtained. Two beam splitting and fiber injection modules, one for each wavelength, were utilized to transform the single laser input beam into six parallel fiber channels. Four of the channels were provided for high output energy and two for low energy monitoring. In addition to the 12 fiber optical outputs, full aperture 1061 nm and 530 nm output ports were provided with independent energy adjustments. The entire laser system was packaged into a rugged 0-ring sealed aluminum housing to maintain cleanliness. The housing measured 18" x 22" x 2.75" and weighed 43.5 pounds. The capability to externally select wavelength, beam format (fiber coupled or full aperture) and output energy was provided. This was to preserve internal cleanliness and facilitate system operation in dirty environments. Alignment strategies and performance results including laser efficiency, far field beam divergence, nonlinear conversion efficiency, fiber-to-fiber energy uniformity, and fiber output intensity profiles will be presented.
Oxygen isotopic compositions of DSDP Site 480 diatoms: Implications and applications

Abstract The oxygen isotope composition of marine diatoms from hydraulic piston-cored samples of DSDP Site 480 vary widely, reflecting the great temperature variations and large isotopic changes of surface water in the Gulf of California. Nevertheless, the results can be correlated with standard oxygen isotope records for the late Quaternary based on carbonates (such as the record of core V19-29). The diatom-based results also parallel oxygen isotope data on benthic foraminifera from Site 480, thus confirming that signals of environmental changes have been retained in the diatom oxygen isotope record throughout the section. The data therefore allow us to assign an oxygen isotope stratigraphy and to define the chronology of Site 480.
SAP97 regulates Kir2.3 channels by multiple mechanisms

We examined the impact of coexpressing the inwardly rectifying potassium channel, Kir2.3, with the scaffolding protein, synapse-associated protein (SAP) 97, and determined that coexpression of these proteins caused an approximately twofold increase in current density. A combination of techniques was used to determine if the SAP97-induced increase in Kir2.3 whole cell currents resulted from changes in the number of channels in the cell membrane, unitary channel conductance, or channel open probability. In the absence of SAP97, Kir2.3 was found predominantly in a cytoplasmic, vesicular compartment with relatively little Kir2.3 localized to the plasma membrane. The introduction of SAP97 caused a redistribution of Kir2.3, leading to prominent colocalization of Kir2.3 and SAP97 and a modest increase in cell surface Kir2.3. The median Kir2.3 single channel conductance in the absence of SAP97 was ∼13 pS, whereas coexpression of SAP97 led to a wide distribution of channel events with three distinct peaks centered at 16, 29, and 42 pS. These changes occurred without altering channel open probability, current rectification properties, or pH sensitivity. Thus association of Kir2.3 with SAP97 in HEK293 cells increased channel cell surface expression and unitary channel conductance. However, changes in single channel conductance play the major role in determining whole cell currents in this model system. We further suggest that the SAP97 effect results from SAP97 binding to the Kir2.3 COOH-terminal domain and altering channel conformation.
Federal Operation of Railroads During the War

Reasons why the roads were taken over by the government, 577. — The contract, 582. — Federal operation, 587. — Labor conditions, 602. — Rate increases, 606. — Capital expenditures and the revolving fund, 609. — Relation of the railroad administration to existing regulating agencies, 611. — The future, 617.
Changes in gastroesophageal reflux in patients with nasogastric tube followed by percutaneous endoscopic gastrostomy.

Background/Purpose Despite frequent use of percutaneous endoscopic gastrostomy (PEG) for enteral feeding, the relationship between it and gastroesophageal reflux (GER) remains an incompletely answered question. We conducted this study to compare the GER between the same patients fed with a nasogastric (NG) tube and later with a PEG tube. Methods We enrolled 15 patients who had received NG tube feeding for > 6 months and were about to receive PEG tube insertion. We used Ponsky's pull method with 24 Fr feeding tubes. They received two GER scans, one just before PEG tube insertion and another 1 week after insertion. We drew regions of interest of radioactivity in the esophagus and stomach manually. The ratios of radioactivity of the region of interest in the esophagus over the stomach (GER ratio) were calculated to evaluate the severity of GER and compared. Results The GER ratios of these patients were all small and Conclusion Our study demonstrates by scintigraphy a small but significant reduction of GER after shifting from NG to PEG tube feeding.
Calcium ethylenediaminetetraacetate (CaEDTA) toxicity: Time- and dose-response studies on intestinal DNA synthesis in the rat

Abstract The effect of CaEDTA on intestinal DNA synthesis was studied by measuring the incorporation of [methyl-3H]thymidine. An ip injection of thymidine (0.25 μCi/g body weight) was given 1 hr before sacrifice. DNA was extracted from a 10% (w/v) homogenate of mucosal scrapings by a modification of the Schmidt-Thannhauser procedure. Radioactivity in the DNA fraction was assayed by liquid scintillation counting. Dose-response studies showed that a constant iv infusion of 3.0 mmoles/kg/24 hr for 24 hr was required to produce a significant inhibition of DNA synthesis. Time-response studies revealed that 18 hr of CaEDTA infusion at a dosage of 6 mmoles/kg/24 hr were required for significant inhibition of DNA synthesis; the degree of inhibition occurring arabinoside (250 mg/kg) injection. Although folic acid (250 mg/kg) did not protect, the infusion of ZnEDTA, CoEDTA, or ZnCaEDTA afforded complete protection against inhibition of DNA synthesis. Even when the rats were moribund following CaEDTA administration, the intestine was capable of recovering its ability to synthesize DNA. This recovery was significantly enhanced by supplementation with zinc, but not by cobalt or manganese. When parenteral alimentation was employed, the survival of the rats was markedly improved. It is proposed that zinc serves as a low-molecular weight nutrient essential to initiation of DNA synthesis and that the mechanism of inhibition of DNA synthesis during the administration of CaEDTA may be the blocking of normal zinc uptake into the cell. Since the intestine is rapidly regenerating at a time when the rat is moribund it is suggested that inhibition of DNA synthesis in the intestine is not the direct cause of death.
Kinetics of H 2 passivation of P b centers at the (111) Si- SiO 2 interface

This paper is concerned with the determination of the kinetic parameters and the chemical reactions that characterize the passivation of P/sub b/ centers with molecular hydrogen. P/sub b/ centers are paramagnetic defects at the (111) Si-SiO/sub 2/ interface. In this study P/sub b/ centers associated with thermal oxides grown on (111) silicon substrates at 850 /sup 0/C were measured with electron paramagnetic resonance. We observe that the P/sub b/ resonance appears to be unaffected by subsequent in situ vacuum anneals for temperatures up to at least 850 /sup 0/C.
The European Union at the Ballot Box?: European Integration and Voting Behavior in the New Member States

Scholars have developed a large body of knowledge on the domestic underpinnings and effects of European integration. Students of the European Union (EU) have devoted considerable attention to the s...
Resolution tolerance in an automated forest land evaluation model

Abstract The United States Department of Agriculture Soil Conservation Service (SCS) Land Evaluation and Site Assessment (LESA) model was developed in direct response to the National Farmland Protection Policy Act as a consequence of ever increasing demands on the land for nonagricultural uses. LESA's land evaluation (LE) subsystem is a portion of the model designed to determine physical quality of the land for agricultural uses. Previous research has shown that parts of the LESA model can be implemented in automated geographic information systems (GIS). However, no implementation of the forest LE subsystem has been implemented on a CIS, therefore requiring evaluation of land for forestry to be performed manually, one land parcel at a time. Nor have any studies indicated the necessary cell resolution for later incorporation of the LE subsystem within the LESA model. This paper describes a prototype implementation of the forest LE subsystem within a micro-computer based GIS at four separate resolutions. The objective of this project was to test its adaptability to GIS implementation and to ascertain its sensitivity to resolution changes. Results show that the forest LE subsystem is readily adaptable both to GIS implementation and final merger with the site assessment (SA) portion of the LESA model. The model showed little change in outcome as a result of resolution change. Categorical simplification of the modeling process and the broad class values utilized produces this lack of resolution sensitivity, demonstrating that resolution can be selected based on the needs of the SA subsystem.