cssi/SciSciGPT-SciSciNet huggingface dataset:
Grid evolution for oxidation simulation using a quadtree based grid generator

Grid and geometry movement algorithms for oxidation simulation are presented using the grid/geometry server Forest. Initial grid generation is performed using a quadtree region decimation algorithm. An oxidation solver is used to compute node velocities and the maximum time step is determined from geometry and grid considerations. The boundary nodes are then moved and geometry singularities like loop formation and region crashes are detected and removed. All the mesh nodes are moved and retriangulation is performed if necessary. The quadtree is rehashed and new triangles are allocated to conform to the new geometry. This algorithm guarantees a high grid quality at all times with minimal grid changes between time steps. >
Implementation of an optimal task allocation strategy

The author describes the implementation of a task allocation algorithm for multiprocessing systems, providing a simulation package to allocate tasks among identical processors. The proposed model provides an optimal task-assignment strategy for distributed programs by using the graph theoretical approach proposed by W. Chu et al. (1980). This approach discusses the interconnections between the modules, which are distributed over many processors to take advantage of parallel processing. The simulation package that is used to simulate the task allocation is written in APL. It generates run-times, communication delays, and execution times for the tasks to be distributed. It then optimizes the system execution time and recommends a task allocation scheme based on these values. In addition, the author provides an allocation strategy based on simulation results. In particular, he focuses on the optimal values of the system run-time and communication delay, and subsequently the system execution time. >
Cascade multilevel inverters for utility applications

Cascade multilevel inverters have been developed by the authors for utility applications. A cascade M-level inverter consists of (M-1)/2 H-bridges in which each bridge has its own separate DC source. The new inverter: (1) can generate almost sinusoidal waveform voltage while only switching one time per fundamental cycle, (2) can eliminate transformers of multipulse inverters used in conventional utility interfaces and static VAr compensators, and (3) makes possible direct parallel or series connection to medium- and high-voltage power systems without any transformers. In other words, the cascade inverter is much more efficient and suitable for utility applications than traditional multipulse and pulse width modulation (PWM) inverters. The authors have experimentally demonstrated the superiority of the new inverter for reactive power (VAr) and harmonic compensation. This paper summarizes features, feasibility, and control schemes of the cascade inverter for utility applications including utility interface of renewable energy, voltage regulation, VAr compensation, and harmonic filtering in power systems. Analytical, simulated, and experimental results demonstrate the superiority of the new inverters.
The influence of label co-occurrence and semantic similarity on children’s inductive generalization

Semantically-similar labels that co-occur in child-directed speech (e.g., bunny-rabbit) are more likely to promote inductive generalization in preschoolers than non-co-occurring labels (e.g., lamb-sheep). However, it remains unclear whether this effect stems from co-occurrence or other factors, and how co-occurrence contributes to generalization. To address these issues, preschoolers were exposed to a stream of semantically-similar labels that don’t co-occur in natural language, but were arranged to co-occur in the experimental setting. In Experiment 1, children exposed to the co-occurring stream were more likely to make category-consistent inferences than children in two control conditions. Experiment 2 replicated this effect and provided evidence that co-occurrence training influenced generalization only when the trained labels were categorically-similar. These findings suggest that both co-occurrence information and semantic representations contribute to preschool-age children’s inductive generalization. The findings are discussed in relation to the developmental accounts of inductive generalization.
Conservation Laws of the general theory of relativity

A fundamental method of approach to the formulation of the conservation laws of the general theory of relativity is presented. This approach is based on the symmetry properties which are admitted by the specific physical space-times under consideration and which underly the conservation laws in differential form that are shown to follow from a generally covariant generator. This method embraces procedures which permit the proper conservation laws of the field to be formulated in a consistent and well-defined manner. For example, if the total energy of a physical system characterized by a solution of Einstein’s field equations is conserved, then this conserved quantity may be formulated in any other co-ordinate system or frame of reference related to the original co-ordinate representation by transformations of the general form -xi=xi (x1, x2, x3, x4). Symmetry properties characterized by groups of motions (Killing vectors) of given space-times are considered in detail. The conservation laws of energy, linear momentum, and angular momentum of the theory of general relativity follow, if admitted, as an immediate consequence of these motions. The mechanical and field conservation laws that follow in consequence of the Riemannian geometry of space-time admitting symmetry properties more general than motions are considered in detail in a second paper, which follows in this issue.
VEGF siRNA Delivery System Using Arginine-Grafted Bioreducible Poly(disulfide amine)

Small interfering RNAs (siRNAs) are able to silence their target genes when they are successfully delivered intact into the cytoplasm. Delivery systems that enhance siRNA localization to the cytoplasm can facilitate gene silencing by siRNA therapeutics. We describe an arginine-conjugated poly(cystaminebisacrylamide-diaminohexane) (poly(CBA-DAH-R)), a bioreducible cationic polymer, as an siRNA carrier for therapeutic gene silencing for cancer. After intracellular uptake of the siRNA/poly(CBA-DAH-R) polyplexes, the reductive environment of the cytoplasm cleaves the disulfide linkages in the polymeric backbone, resulting in decomplexing of the siRNA/poly(CBA-DAH-R) polyplexes and release of siRNA molecules throughout the cytoplasm. The siRNA/poly(CBA-DAH-R) polyplexes, which demonstrate increased membrane permeability with arginine modification, have a similar level of cellular uptake as siRNA/bPEI polyplexes. The VEGF siRNA/poly(CBA-DAH-R) polyplexes, however, inhibit VEGF expression to a greater degree than VEGF siRNA/bPEI in various human cancer cell lines. The improved RNAi activity demonstrated by the VEGF siRNA/poly(CBA-DAH-R) polyplexes is due to enhanced intracellular delivery and effective localization to the cytoplasm of the VEGF siRNAs. These results demonstrate that the VEGF siRNA/poly(CBA-DAH-R) polyplex delivery system may useful for siRNA-based approaches for cancer therapy.
Yield and Quality of Alfalfa as Affected by Harvesting and Storage Methods

Abstract Losses in harvesting and storage were determined for several methods of packaging alfalfa hay. Swathing or swathing and raking had little effect on losses of dry matter or on protein content. Alfalfa put up as silage, stacks, rectangular bales (25 kg), large round bales (544 kg), and small round bales (295 kg) retained 90.1, 89.4, 83.5, 69.8, and 67.4% of dry matter potentially available. Silage and rectangular bales of first crop alfalfa were higher in protein than small round bales. Large round bales retained over 95% of dry matter during storage. Stacks of alfalfa retained 85% of dry matter when stored outside for 6 to 7 mo and 90.4% of dry matter when stored under roof with open sides. Recovery of dry matter from rectangular bales stored under roof was 101% for first crop material and 87.4% for second crop.
Effects of random motility on growth of bacterial populations.

A spatially distributed mathematical model is developed to elucidate the effects of chemical diffusion and cell motility as well as cell growth, death, and substrate uptake on steady-state bacterial population growth in a finite, one-dimensional, nonmixed region. The situation considered is growth limited by a diffusing substrate from an adjacent phase not accessible to the bacteria. Chemotactic movement is not considered in this paper; we consider only “randomwalk”-type random motility behavior here. The following important general concepts are suggested by the results of our theoretical analysis: (a) The significance of random motility effects depends on the magnitude of the ratioμ/kL 2, whereμ is the bacterial random motility coefficient,k is the growth rate constant, andL is the linear dimension of the confined growth region. (b) In steady-state growth in a confined region, the bacterial population size decreases asμ increases. (c) The effect ofμ on population size can be great; in fact, sometimes relative population sizes of two species can be governed primarily by the relative values ofμ rather than by the relative values ofk.
Larval Growth as a Method of Screening Triticum sp. for Resistance to the Cereal Leaf Beetle

Larval growth was used to screen 2 groups of Triticum Accessions for resistance to the cereal leaf beetle, Oulema melanopus (L.). The 2 groups consisted of accessions that had either resistant or susceptible reactions to beetle attack in a field nursery. Weight gains ami survival ratings of the beetle larvae were computed for each Triticum accession. About 20% of the group that had resistant reactions in the field nursery were highly resistant to larval growth, None of the group that had susceptible reactions in the field nursery had a resistant reaction. Thus larval growth clarified and substantiated the ratings in the field nursery of resistant reactions to the cereal leaf beetle.
In vitro transcription of a late class of phage SP01 genes

Bacillus subtilis phage SP01 directs the synthesis of at least six temporally defined classes of phage-specified transcripts1. Synthesis of the two earliest classes of phage RNA (e and em) does not require phage protein synthesis, while the synthesis of middle (m and m1l) and late (m2l and l) transcripts requires the protein product of regulatory gene 28 and the products of regulatory genes 33 and 34, respectively2,3. The discovery of SP0l-induced polypeptides associated with B. subtilis RNA polymerase suggested that the products of SP01 regulatory genes could control transcription by interacting directly with the host RNA polymerase4,5. In support of this idea, we reported6 that a form of RNA polymerase from SP01-infected cells copies middle RNA almost exclusively from the heavy (H) strand of native SP01 DNA, the DNA strand from which middle and late genes are transcribed in vivo. This enzyme contains an SP01-induced polypeptide termed IV (molecular weight 26,000) that is now known to be the product of regulatory gene 28 (T. Fox, R. L. and J. P., manuscript in preparation). Accurate middle gene transcription by this phage-modified RNA polymerase does not require σ factor but is apparently dependent on a newly described host subunit of RNA polymerase called δ (molecular weight 21,500)6. Other workers have also reported the preferential synthesis of middle RNA by RNA polymerase from phage-infected B. subtilis7,8. Here we report that in the presence of host δ protein a form of RNA polymerase containing phage-induced polypeptides termed V (molecular weight 24,000) and VI (molecular weight 13,500) asymmetrically transcribes a class of SP01 late genes in vitro.
MEASUREMENTS OF THE CRAZE-BULK INTERFACIAL ACTIVE ZONE

The width of the active zone, a region of strain softened material at the craze-bulk interface, was measured as a function of temperature in polystyrene (PS) using a gold decoration technique. Thin trilayer films of PS (total thickness 0.6 μm) with a central layer of buried gold “islands” were made. The films were strained at a controlled rate and various temperatures. When the films crazed, the gold particles act as markers which reveal the deformation of the PS. The strain in the PS could be seen in transmission electron microscopy (TEM) as a change in areal density of the gold particles. The width of the active zone was determined by measuring the distance between the edge of the change in areal density of the gold particles and the craze-bulk interface. It was found that the width of the active zone was a function of the distance behind the craze tip at room temperature. The width of the active zone was ∼10 nm at the craze tip and increased linearly to a value of ∼25 nm at a distance 250 to 300 μm from the craze tip. The active zone width was independent of the distance from the craze tip for distances greater than 300 μm. The active zone width at the craze tip is in good agreement with previously reported results. The higher strain rates at the craze tip are believed to be responsible for the change in the width of the active zone as a function of distance behind the craze tip. The active zone width increased linearly with increasing temperature from 25 nm at room temperature to 60 nm at 93 °C. The increase in the active zone width can be accounted for by the decrease in strain softening of PS at higher temperatures.
Prehistoric Art and Ideology1

THE material remains of past civilizations sometimes include art. Where this is so, as in the spectacular case of Upper Paleolithic art in Western Europe, we may be able to add an ideological dimension to our understanding of the ancient people. Traditional anthropological interest in art treated the subject as an isolated ethnographic category, focused almost exclusively on the technique of art-making, on the iconography, and on the uses to which art is put. But attention has turned increasingly to questions about the ties between art and other aspects of culture. For example, monographs by Mills (1953) and McAllester (1954), produced under the aegis of the Harvard Values Study project, have looked for relationships between esthetic values in Navaho art and music and Navaho value culture as a whole. Malraux's Voices of Silence (1953) exhibits a convergent trend in art history. These and similar studies are laying the foundation on which efforts to interpret prehistoric art must rest. Translating into achievement the prospect of reconstituting prehistoric "idea culture" through the study of prehistoric art depends upon finding ways and means for archeologists to ask, however indirectly, the same questions which ethnologists increasingly pursue among recent and living art-makers. If relationships between art and other parts of culture can be discerned and described in individual cultures and compared across cultures so as to yield generalizations, if we can make a reasonable case for the idea that a people's art is patterned by the point of view of their culture, if we can suggest the ways in which art exhibits this patterning, we might hope to put the lessons learned to work in behalf of a plausible reconstruction of the attitudes and outlook of a prehistoric people. We might gain a means of narrowing the gap between that span of time for which we know something of man as an economic animal and that much shorter period for which we are acquainted with him as a thinking, believing, feeling creature. The concern of this paper is two-fold: What kind of controls on interpretation can we derive from the study of ethnographic materials? And, what problems can we approach fruitfully through the analysis of art style? The crucial general issues about the "nature of artistic behavior" and the character of the "relationship between Art and Culture" are not confronted directly.
Bonding of antimony on GaAs(110): A prototypical system for adsorption of column-V elements on III-V compounds

It is shown that the atomic structure of column-V-element overlayers on GaAs(110) is in the form of a zigzag chain arrangement by a combination of detailed experimental investigation (using both photoemission electron spectroscopy and low-energy electron diffraction) and simple theoretical analysis. Antimony (Sb), used as a representative column-V element, spontaneously forms zigzag chains which are parallel to and in registry with the zigzag chains of the GaAs(110) surface when deposited at room temperature. The close lattice match between the size of the GaAs(110) surface unit cell and the zigzag chain constructed with Sb favors a near-ideal (dehybridized Sb orbitals in the Sb--Sb bonds) structure for the adatom chain when bonded to the substrate. The result is a new very-well-ordered atomic arrangement on the surface with two Sb atoms inside the GaAs(110) surface unit cell. From simple calculations, it is shown that the dehybridization of the states of the column-V atom in the zigzag chain structure results in a surprisingly narrow (approx.1.5-eV) band of bonding p states, when compared to the approx.12-eV bandwidth of bonding p states in a linear chain. Strong evidence for this narrow band of Sb p states is shown in the photoemission data. Two schemes for attachmentmore » of the zigzag chain to the GaAs(110) surface are presented and their electronic structure is analyzed.It is concluded that the combination of simple theoretical and detailed experimental approaches employed here are useful, in general, for determining the structure of column-V overlayers on III-V semiconductor surfaces.« less
Host-feeding and oviposition on Musca domestica by Spalangia cameroni, Nasonia vitripennis, and Muscidifurax raptor (Hymenoptera: Pteromalidae) influences their longevity and fecundity.

The longevity and fecundity of 3 pteromalid species in response to 3 host-availability treatments were charted. In Treatment 1, 20 hosts were supplied daily after mating; in Treatment 2, 1 host was supplied initially for 24 hours followed by no hosts for 48 hours, with 20 hosts being supplied thereafter; and in Treatment 3, no hosts for 72 hours after mating followed by 20 supplied daily. The adults of Spalangia cameroni Perkins and Nasonia vitripennis (Walker) required hosts when very young for maximum longevity and oviposition; Muscidifurax raptor Girault and Sanders performed best when deprived of hosts for a minimum of 4 days after emergence. Responses were proportional to the intensity of host-feeding and oviposition. Host availability of young adult females apparently influences their reproductivity and behavior during their entire life span. The extent and direction that behavior is affected depends on the species involved. Results are compared with those of other workers.
The meaning of health communication: Maybe they just don't know what they don't know?

AbstractWith increasing complexities in healthcare and a rise in medical errors, the literature has demonstrated links between health communication methods, patient safety, and adherence to health protocols. The purpose of this study was to understand the level of knowledge and perceived meaning of health communication among doctoral (DPT) students and experienced physical therapists (PTs), and to explore health communication methods used in the field. Practicing PTs and DPT students were interviewed for this qualitative research in academic, practice, conference, and home settings, but lessons learned could apply to clinicians and students from other disciplines as well. Findings suggest that, although patient–practitioner (interpersonal) communication topics may be embedded into professional curricula, gaps exist in awareness and knowledge of meso- and macro-level health communications. Though PT education provides rigorous technical training in diagnosis, evaluation, treatment, and culture- and age-rel...
Potential Health Effects of Light‐Duty Diesel Exhaust

The purpose of this paper is to review briefly the evidence for potential human health effects that may result from increased dieselization of the nation's light-duty vehicle fleet. An effort is made to put the potential effects into perspective, both with regard to projected excess cancer deaths, should diesel exhaust be carcinogenic to humans, and in relation to past use of vehicles using leaded gasoline. Certain related research needs are highlighted. Available data concerning the relationship between diesel emissions, ambient air quality, and human health are summarized. On the basis of exposure estimates and relative potency factors, the authors conclude that the best estimate of the number of excess annual U.S. lung cancer deaths as a result of lifetime exposure to light-duty diesel particulate under 1990 conditions is between 80 and 1500. Available data suggest that the carcinogenic hazard of exhaust from vehicles burning leaded gasoline may be an order of magnitude greater, on a per mile basis, than that of diesel engines. The hazard of emissions from diesel are, in turn, probably an order of magnitude greater than that of gasoline engines with catalytic converters burning unleaded gasoline. Important research needs identified by the authors include determining whether diesel exhaust is in fact a human carcinogen, studying the effect of atmospheric chemical transformation of organics in diesel exhaust on the toxicity of the exhaust, making a better determination of the relative carcinogenicity of diesel and gasoline exhausts, and determining whether exposure to diesel exhaust contributes to the development or exacerbation of chronic lung disease or of respiratory illness, especially in the very young and the aged.
Insecticides affecting ion transport.

Abstract Ion transport phenomena have been reviewed and shown to be an integral part of many physiological processes in the nervous system including peripheral nerve, synaptic junctions and neuromuscular connections. Many instances where insecticides have been demonstrated by neurophysiological and/or biochemical techniques to interfere with ion transport processes have been indicated. In particular, organochloine insecticides have been demonstrated to alter the ability of excitable tissue in regard to selective permeability of Na+ and K+ ions associated with the action potential of a propagated impulse. In neuromuscular junctions a variety of insecticides appear to upset the binding of Ca+ with the sarcoplasmic reticulum. Transmitter release associated with ion transport was also reported to be affected by certain insecticides and other pesticides. Description of attempts to elucidate the biochemical basis for the alteration in ion movements as observed by neurophysiological techniques were described. A major emphasis of the biochemical approaches included studying ATPase enzymes. These enzymes are involved in various aspects of ion transport and indeed inhibition of ATPase associated with the sarcoplasmic reticulum was claimed to be involved with muscle contractions caused by the insecticides. Aspects of inhibition of ATPases in peripheral nerve were described and in particular a Ca+ sensitive ATPase that was inhibited by DDT at low concentrations was reported. Correlations between this enzyme and the resurfacification of Ca2+ on the axonic membrane were presented as a possible mode of action of DDT in peripheral nerve. Problems of insecticides affecting ion transport are of interest from the viewpoint of basic physiology in that these compounds can and have been used as tools to study physiological processes. These studies are also of importance in determining the safety and acute and chronic toxicity of insecticides.
Interplay between Microscopic Diffusion and Local Structure of Liquid Water

We present a quasielastic neutron scattering (QENS) study of single-particle dynamics in pure water, measured at temperatures between 256 and 293 K along an isobaric path at 200 MPa. A thorough analysis of the spectral line shapes reveals a departure from simple models of continuous or jump diffusion, with such an effect becoming stronger at lower temperatures. We show that such a diverging trend of dynamical quantities upon cooling closely resembles the divergent (anomalous) compressibility observed in water by small-angle diffraction. Such an analogy suggests an interesting interplay between single-particle diffusion and structural arrangements in liquid water, both bearing witness of the well-known water anomalies. In particular, a fit of dynamical parameters by a Vogel-Tammann-Fulcher law provides a critical temperature of about 220 K, interestingly close to the hypothesized position of the second critical point of water and to the so-called Widom line.
The Prestel system and information retrieval

This article aims at explaining how viewdata systems work, with a particular emphasis on Prestel. Reference is made to the types of information available from both viewdata and teletext systems, together with suggestions as to how they should be used. Both the system hardware and software are discussed as is the configuration of computers providing the Prestel public service.
Dectin-1-triggered recruitment of light chain 3 protein to phagosomes facilitates major histocompatibility complex class II presentation of fungal-derived antigens

Dectin-1 is a pattern recognition receptor that is important for innate immune responses against fungi in humans and mice. Dectin-1 binds to β-glucans in fungal cell walls and triggers phagocytosis, production of reactive oxygen by the NADPH oxidase, and inflammatory cytokine production which all contribute to host immune responses against fungi. Although the autophagy pathway was originally characterized for its role in the formation of double-membrane compartments engulfing cytosolic organelles and debris, recent studies have suggested that components of the autophagy pathway may also participate in traditional phagocytosis. In this study, we show that Dectin-1 signaling in macrophages and bone marrow-derived dendritic cells triggers formation of LC3II, a major component of the autophagy machinery. Further, Dectin-1 directs the recruitment of LC3II to phagosomes, and this requires Syk, activation of reactive oxygen production by the NADPH oxidase, and ATG5. Using LC3-deficient dendritic cells we show that whereas LC3 recruitment to phagosomes is not important for triggering phagocytosis, killing or Dectin-1-mediated inflammatory cytokine production, it facilitates recruitment of MHC class II molecules to phagosomes and promotes presentation of fungal-derived antigens to CD4 T cells.
Finite element analysis of PZT tube scanner motion for scanning tunnelling microscopy

SUMMARY This article is a presentation of the results of a finite element method analysis of piezoelectric tube scanners of the type presently in wide use in scanning tunnelling microscopes. The tube scanner moves a tunnelling tip by bending sideways when unsymmetrical voltages are applied to longitudinal stripes of metallization on its walls. It also can be extended and contracted in length by application of symmetrical voltages. One wishes to know the characteristics and magnitudes of the resulting three-dimensional motion. We divided a model tube into radially polarized elements, and constructed a computer program to perform electromechanical stress calculations. The results show the dependence of motion upon applied voltage, tube material, and tube dimensions.
Lattice dynamics of thin layers of molecular nitrogen adsorbed on graphite.

Monolayer and bilayer solid lattices of molecular nitrogen adsorbed on the basal plane surface of graphite are modeled with realistic intermolecular-potential models, and the Helmholtz free energy is evaluated with quasiharmonic lattice dynamics. The stability of herringbone and pinwheel orderings of the layers relative to each other and to the low-temperature three-dimensional solid is determined. There is good agreement with the observed length and energy scales of the monolayer and bilayer lattices. The modeling is consistent with the following succession of lattices: commensurate monolayer herringbone, uniaxially incommensurate monolayer herringbone, monolayer pinwheel, and bilayer pinwheel or bilayer uniaxially incommensurate herringbone.
Explaining Variation in the Effects of Welfare-To-Work Programs:

Evaluations of government-funded training programs often combine results from similar operations in multiple sites. Findings inevitably vary. It is common to relate site-to-site variations in outcomes to variations in program design, participant characteristics, and the local environment. Frequently, such connections are constructed in a narrative synthesis of multisite results. This article uses findings from the evaluations of California's Greater Avenues for Independence (GAIN) program and the National Evaluation of Welfare-to-Work Strategies (NEWWS) to illustrate why it is important to question the legitimacy of such syntheses. The discussion is carried out using a simple multilevel evaluation model that incorporates models of both individual outcomes within sites and variation in program effects across sites. The results indicate that tempting generalizations about GAIN and NEWWS effects are statistically unjustified but that significant progress might be made in identifying the determinants of progr...
Effect of selenium on microbial communities in laboratory microcosms and outdoor streams

Ecological effects of selenium (as sodium selenite) on naturally derived microbial communities were evaluated in laboratory microcosms and in outdoor experimental streams at the U.S. Environmental Protection Agency (U.S. EPA) Monticello Ecological Research Station (MERS). Microcosms were continuously dosed for 21 days at selenium concentrations ranging from 0 to 160μg Se/L. Outdoor streams were continuously dosed at 0, 10, and 30 μg Se/L, the highest concentration approximating the current U.S. EPA water quality criterion. In laboratory microcosms, protozoan species richness was reduced by 20%, and chlorophyll and hexosamine levels were reduced by 40% at μ80 μg Se/L. Total biomass and carbohydrate levels decreased with increasing Se, but these effects were not significant. Selenium had no effect on microcosm production to respiration ratios. In outdoor streams, microbial community biomass collected on artificial substrata was 2–3 times greater than in the laboratory. In general, adverse effects were not observed, confirming laboratory estimates of no adverse effects at <80 μg Se/L. However, low doses (10μg Se/L) consistently stimulated microbial biomass (protein, chlorophyll, hexosamine) and elevated production to biomass (P/B), consistent with reports of Se stimulation of algal growth. The highest Se dose (30 μg/L) caused decreased primary production and decreased P/B compared to controls. Experiments showed that ecological responses of laboratory microcosms and outdoor experimental ecosystems are similar, and are at least as sensitive as standard toxicological responses.
Effect of Propylthiouracil and Methimazole on the Oxygen Consumption of Hypothyroid Rats Receiving Thyroxine or Triiodothyronim

The calorigenic response to thyroxine and triiodothyronine has been compared in hypothyroid rats treated with either propylthiouracil or methimazole. Propylthiouracil reduced the calorigenic response to thyroxine, but methimazole did not. Neither methimazole nor propylthiouracil diminished the calorigenic response to triiodothyronine, and methimazole may even have increased this response when 80μg/day of triiodothyronine was administered. When methimazole was replaced by propylthiouracil in the diet of rats treated with thyroxine, the oxygen consumption fell slowly over a period of 2 weeks, but there was little rise in oxygen consumption during the 2 weeks after the diet was changed from propylthiouracil to methimazole. (Endocrinology 81: 1018, 1967)
Quantifying Vinyl Monomer Coordination to CuI in Solution and the Effect of Coordination on Monomer Reactivity in Radical Copolymerization

The association/dissociation equilibrium between vinyl monomers (M) and the complex [CuI(PMDETA)]BPh4 (where PMDETA = N,N,N‘,N‘ ‘,N‘ ‘-pentamethyldiethylenetriamine) to form [CuI(PMDETA)(π-M)]BPh4 was studied by variable temperature 1H NMR. The enthalpy and entropy of coordination and the relative binding constants of methyl acrylate (MA), 1-octene (Oct), styrene (Sty), and methyl methacrylate (MMA) were determined. The affinity of the monomers to the CuI center decreased in the order MA > Oct > Sty > MMA with formation constants (at room temperature) equal to 760, 320, 250, and 6 M-1, respectively. Quantification of this equilibrium process allowed the study of the effect that coordination has on the reactivity of the monomer in free radical polymerization. During these studies, an additional side reaction between free radical azo-initiators (AIBN and V-70) and the CuI complex was identified and analyzed. Additionally, the consequence of monomer coordination to CuI in atom transfer radical polymerization...
Production of Strange-Particle Resonant States by 2.1-BeV/ c π − Mesons

Interactions of mesons ( pi /sup -/) on protons at about 2.1 Bev/c resulting in the production of a visible hyperon are measured and fitted kinematically. The distributions of the interactions resulting in LAMBDA pi K and SIGMA pi K final states are shown. An I = 0 SIGMA pi resonance is observed at a mass (M/sub SIGMA pi /) of 1405 Mev, and it is suggested that this resonance be identified with a bound S/sup 1/2 state of the KN system. A second SIGMA pi / resonance at M/sub SIGMA pi / = 1510 to 1560 Mev, K pi resonances at M/sub K pi = 730 and 885 Mev, and a LAMBDA pi resonance at M/sub LAMBDA pi / = 1385 Mev, are also studied. The widths, strengths, and masses of these resonances are discussed. (T,F.H.)
Estimates of acetaminophen (paracetomal)‐associated overdoses in the United States

Objective To estimate the number of acetaminophen-associated overdoses in the United States and identify possible risk factors for intervention. Methods The investigators obtained estimates of acetaminophen-associated overdoses using different national databases. Two emergency room databases, a hospital discharge database, a national mortality file, and a poison surveillance database were used to identify cases. The FDA's spontaneous reporting system was searched to identify possible root causes for overdoses. Results Analysis of national databases show that acetaminophen-associated overdoses account for about 56,000 emergency room visits and 26,000 hospitalizations yearly. Analysis of national mortality files shows 458 deaths occur each year from acetaminophen-associated overdoses; 100 of these are unintentional. The poison surveillance database showed near-doubling in the number of fatalities associated with acetaminophen from 98 in 1997 to 173 in 2001. AERS data describe a number of possible causes for unintentional acetaminophen-associated overdoses. Conclusions Each year a substantial numbers of Americans experience intentional and unintentional acetaminophen-associated overdoses that, in severe cases, lead to serious illness and possible death. This summary of a series of analyses highlights the need for strategies to reduce this public health burden.
Using Molecular Mechanics to Model the Movement and Relaxation of Radical Pairs Created By Photolysis of Single Crystals of Acetyl Benzoyl Peroxide (ABP)

Abstract The structure of isolated crystal defects is studied by molecular mechanics techniques, using experimental data to constrain the relaxation of configurational energy and to escape from local energy minima. A “Surface Walking” algorithm helps determine the reaction path among the metastable intermediate structures that evolve upon warming. Applying these techniques to ABP gives good results even without relaxing surrounding molecules.
Spectrochemical Analysis of Trace Impurities in Copper Using Copper Fluoride as a Carrier-Distillation Agent:

A comprehensive study has been made of the efficiency of copper fluoride as a carrier for the quantitative determination of more than thirty impurities in high purity metallic copper. Although other halides of copper and silver have been shown to improve the sensitivity of their detection, copper fluoride was found to be by far the most versatile and effective. The carrier is added directly to the metallic sample, making the method both simple and unusual. The line intensities of the impurities are apparently independent of the size of the copper sample and dependent only on the quantity of impurities present, a fact which greatly simplifies both calibration and analysis. The limits of detection range down to 10 ppb and are lower than those reported by other spectrographic methods in a number of cases. The results obtained for 15 different elements gave a coefficient of variation of 6.5% on 15 replicate samples. Since extremely pure copper fluoride is vital, a simple method for its preparation is described.
Flexible soft glass capillary columns vs. flexible fused silica capillary columns for gas chromatography-a critique

The gas chromatographic use of flexible thin walled soft glass capillary columns coated with non-polar stationary phases is compared to similar columns made of fused silica glass. With non-polar soft glass columns, the use of surface roughening viagaseous HCI followed by a Carbowax 20 M pretreatment gave adsorptive phenomena, and thermal instability. With very polar soft glass columns where a variety of cyanopropyl silicone phases were coated directly onto the NaCI crystal matrix, adsorptive effects were again prominent and frequent break-down in film stability with time, was also observed. These undesirable effects were due to the presence of metal oxides in the soft glass. Attempts to remove these materials from the thin walled soft glass surface by means of acid leaching produced significant brittleness. This deleterious result was further increased by attempts at high temperature silylation or polysiloxane deactivation. In sharp contrast, the fused silica surface was essentially free of metal oxides and the surface silanol groups are easily neutralized by silylation or polysiloxane deactivation techniques. No brittleness was observed following these procedures. An increasing series of high molecular weight, viscous, polymeric vinyl containing non-polar and highly polar stationary phases have been produced which readily wet the surface of the fused silica and are easily crosslinked in the presence of free radical generators. These columns are essentially free of all the problems noted with flexible thin walled soft glass. When all of the parameters involved in the fabrication of a glass capillary column are assessed, it appears at this time, that the flexible fused silica glass column with cross linked phases approaches the “ideal” capillary column.
Distribution of glutamic acid, aspartic acid, γ-aminobutyric acid and glycine in six areas of cat spinal cord before and after transection

Summary 1. Determination of the concentration of glutamate, glycine, γ-aminobutyric acid, aspartate and total TCA soluble amino acids was made in six areas of the spinal cord (dorsal funiculus, dorsolateral funiculus, dorsal gray, ventral gray, ventral funiculus, and ventrolateral funiculus) from normal, sham operated cats and cats whose cords were transected 2 and 21 days earlier. 2. After 21 days there was a significant drop of glutamate and a drop of glycine in the dorsolateral funiculus. After 2 days no difference from normal data was found except a fall in the mean values of total amino acids in all areas. 3. Selective lesions of cortico-spinal or rubro-spinal tracts did not show any decrease in the aforementioned amino acids. 4. The failure of GABA concentration to decrease after cord section rules out the possibility that GABA is associated with supraspinal descending tracts.
Permissible control of general constrained mechanical systems

This paper develops a unified approach for modeling and controlling mechanical systems that are constrained with general holonomic and nonholonomic constraints. The approach conceptually distinguishes and separates constraints that are imposed on the mechanical system for developing its physical structure between constraints that may be used for control purposes. This gives way to a general class of nonlinear control systems for constrained mechanical systems in which the control inputs are viewed as the permissible control forces. In light of this view, a new and simple technique for designing nonlinear state feedback controllers for constrained mechanical systems is presented. The general applicability of the approach is demonstrated by considering the nonlinear control of an underactuated system.
A Prospective Study of the Catheter Hub as the Portal of Entry for Microorganisms Causing Catheter-Related Sepsis in Neonates

The hypothesis that catheter-related sepsis (CRS) may be preceded by contamination of the catheter hub was tested in neonates with central venous catheters. Cultures of the catheter hub were obtained three times per week. One hundred thirteen catheters were placed in 88 patients. Of 35 episodes of sepsis, 28 were catheter-related, for a catheter sepsis rate of 1.03/100 catheter-days. CRS occurred in 26 (23%) of 113 catheters. In 10 of 28 episodes, the infecting microorganism was cultured from the hub before its culture from blood obtained at the time of clinical sepsis. In an additional 5 cases, a culture of the catheter hub at the time of clinical sepsis yielded the same isolate as the blood culture. Thus, 54% of episodes of CRS were preceded by or coincided with contamination of the hub. The catheter hub may be a major portal of entry for microorganisms causing sepsis in a neonatal intensive care unit.
FUNCTIONAL PROPERTIES OF HYDROLYZED LACTOSE: SOLUBILITY, VISCOSITY AND HUMECTANT PROPERTIES

Three sugar syrups were studied that were equivalent to 70, 90 and 100% hydrolysis of lactose. The viscosity and solubility of the sugars, both individually and as mixtures, were determined within the range 10–60°C. At every temperature, lactose was least soluble, galactose next, and glucose most soluble. Added sugars of the types present in hydrolyzed lactose syrups lowered the solubility (40°C) of the individual sugars. Even so, the maximum soluble sugar solids (TS) content was about the same in solutions representing partially (62.96% TS from 3 sugars) and completely (61.95% TS from 2 sugars) hydrolyzed lactose. Hydrolysis of lactose permits the production of stable syrups with higher TS. The viscosity of hydrolyzed lactose syrup was very similar to that of its individual constituent sugars and to sucrose when the percent TS was 50% or less; at higher percent TS the viscosity tended to be less than that of sucrose. Humectant properties were studied at 20°C. They showed that the water-retention capacity of hydrolyzed mixtures at 20°C and 15–93% relative humidity was very similar to that of sucrose syrups of comparable TS.
Schrödinger operators with matrix potentials. Transition from the absolutely continuous to the singular spectrum

Abstract It is proven that the absolutely continuous spectrum of matrix Schrodinger operators coincides (with the multiplicity taken into account) with the spectrum of the unperturbed operator if the (matrix) potential is square integrable. The same result is also proven for some classes of slower decaying potentials if they are smooth.
Third-order dispersion in femtosecond fiber lasers

We experimentally investigate the effects of third-order dispersion (TOD) on ultrafast sources, using dispersion-compensated femtosecond fiber lasers. By in situ measurement of the intracavity dispersion, we identify spectral resonances that are due to coupling of the cavity pulse energy to dispersive wave components at the phase velocity and group-velocity-matched wavelengths. We obtain pulse widths as short as 91 fs by partially compensating the TOD. We relate the observed effects to consequences for soliton transmission and operation of other solitary-pulse lasers.
Evidence-based medicine: the fourth revolution in American medicine?

Summary:The use of evidence has become a force in American medicine to improve the quality of health care. Funding decisions from payers will demand studies with high-level evidence to support many of the costly interventions in medicine. Plastic surgery is certainly not immune to this national tida
Development of the urostyle during metamorphosis in five species of anurans

Normal development of the urostyle is described during late stages of metamorphosis in five species of anurans: Xenopus laevis (Daudin), Bufo americanus Holbrook, Pseudacris triseriata (Wied), Hyla chrysoscelis Cope, and Rana pipiens Schreber. The developing urostyle of all five species is composed of essentially the same cartilaginous elements: one pair of basidorsals above the notochord and the subtended hypochord. Among the five species there is variation in such details as the number of spinal nerve foramina and the degree of fusion of the basidorsals; however, both the hypochord and basidorsals are very similar in all five genera examined. Consideration of the literature suggests that contradictory descriptions of the developing urostyle result from (1) varied methods of study (alizarin-staining of whole specimens or serial cross-sections), (2) the variety of species examined, and (3) the particular stage of development of the tadpole described by an investigator.
Influence of structural factors in the acridines upon their therapeutic effectiveness. Quantum mechanical parameters

Abstract The electron density at the ring nitrogen ( q ), the energy of the highest occupied molecular orbital (HOMO) and the energy of the lowest empty molecular orbital (LEMO) of a large series of acridine compounds have been calculated by the LCAO method These have been studied in relation to the p K a and to the therapeutic indices of these compounds. For three gram-positive organisms ( Clostridium welchii, Streptococcus pyogenes , and Staphylococcus aureus ) the toxicities of the compounds correlate well with q and LEMO. The correlation for two gram-negative organisms ( Bacterium coli and Proteus ) is not as good. q , HOMO, and LEMO are discussed in terms of the p K a and molecular structures. The correlations of the quantum values and toxicity have been viewed in relation to the possible interaction of the acridines and the cell membrane and DNA in bacteria and trypanosomes.
Alterations in Tau Phosphorylation in Rat and Human Neocortical Brain Slices Following Hypoxia and Glucose Deprivation

Abstract Tau is a microtubule-associated protein which is regulated by phosphorylation. Highly phosphorylated tau does not bind microtubules and is the main component of the paired helical filaments seen in Alzheimer's and related neurodegenerative diseases. Recent reports suggested that patterns of tau phosphorylation changed following ischemia and/or reperfusionin vivo.We used anin vitromodel employing rat and human neocortical slices to investigate changes in tau phosphorylation which accompany oxygen and glucose deprivation. Western blotting with polyclonal and phosphorylation-sensitive Tau-1 monoclonal antisera was used to monitor changes in tau which accompanied conditions of oxygen and glucose deprivation and reestablishment of these nutrients.In vitrohypoglycemia/hypoxia caused tau to undergo significant dephosphorylation in both rat and human neocortical slices after 30 and 60 min of deprivation. This dephosphorylation was confirmed using immunoprecipitation experiments after radiolabeling tau and other proteins with32Pi. Okadaic acid, a phosphatase inhibitor, was able to prevent tau dephosphorylation in both control and ischemic slices. Lubeluzole, a benzothiazole derivative within vivoneuroprotective activity, did not significantly alter patterns of tau phosphorylation. Restoration of oxygen and glucose following varied periods ofin vitrohypoxia/hypoglycemia (15–60 min) led to an apparent recovery in phosphorylated tau. These data suggest that tau undergoes a rapid, but reversible dephosphorylation following brief periods ofin vitrohypoxia/hypoglycemia in brain slices and that changes in tau phosphorylation help determine the extent of recovery following oxygen and glucose deprivation.