cssi/SciSciGPT-SciSciNet huggingface dataset:
MIMO optimal control design: the interplay between the /spl Hscr//sub 2/ and the l/sub 1/ norms

We consider controller design methods which can address directly the interplay between the /spl Hscr/2 and l/sub 1/ performance of the closed loop. The development is devoted to multi-input/multi-output (MIMO) systems. Two relevant multi-objective performance problems are considered each being of interest in its own right. In the first, termed as the combination problem, a weighted sum of the l/sub 1/ norms and the square of the /spl Hscr//sub 2/ norms of a given set of input-output transfer functions constituting the closed loop is minimized. It is shown that, in the one-block case, the solution can be obtained via a finite-dimensional quadratic optimization problem which has an a priori known dimension. In the four-block case, a method of computing approximate solutions within any a priori given tolerance is provided. In the second, termed as the mixed problem, the /spl Hscr//sub 2/ performance of the closed loop is minimized subject to an l/sub 1/ constraint. It is shown that approximating solutions within any a priori given tolerance can be obtained via the solution to a related combination problem.
Effects of short-term hypoxia on platelet counts of mice

Recent studies have shown that long-term hypoxia causes decreased platelet counts in mice and short-term hypoxia increased platelet counts. In an attempt to explain the mechanism that increases platelet counts of mice after exposure to short-term hypoxia, we measured platelet counts, total circulating platelet counts (TCPC), total circulating platelet masses (TCPM), percentages of 35S incorporation, and platelet sizes. Platelet counts, as well as TCPC and TCPM of mice, increased after 1-3 days of hypoxia, but these values were decreased after 6-7 days of hypoxia. Although platelet counts were increased in hypoxic mice, the percentage 35S incorporation into platelets and platelet sizes did not show a concurrent increase. After 6 days of hypoxia, average platelet diameters began to increase as platelet counts decreased. Splenic release did not account for the increase in platelet counts of mice after short-term hypoxia. It seems possible, therefore, that megakaryocytes "shed" platelets into the circulation in response to hypoxia. The platelets that enter the circulation in response to short-term hypoxia are smaller and incorporate less 35S than platelets that are produced in response to acute thrombocytopenia.
Shiga-like toxin-producing Escherichia coli in Seattle children: A prospective study

Abstract Background: The frequency with which stools contain Shiga-like toxin producing Escherichia coli not belonging to serotype 0157:H7 is unknown in the United States. The aim of this study was to determine the frequency with which these E. coli are present in stools from children from Seattle submitted for bacteriologic analysis. Methods: 2225 coliform colonics from 445 stools submitted for bacterial culture from Seattle children were probed with the structural genes of Shigalike toxins I and II in a 1-year prospective study. The adherence and actin aggregating characteristics of these E. coli were subsequently determined. Results: Five (1.1%) patients had non-0157:H7 Shiga-like toxin producing E. coli , a rate of isolation higher than Shigella or Yersinia (0.2% each) but lower than Campylobacter (2.5%), E. coli 0157:H7 (2.9%), or Salmonella (3.4%). Only one of the five patients had bloody diarrhea. None developed hemolytic uremic syndrome. All strains adhered in a localized pattern to, and induced actin aggregation in, HeLa cells, and produced a toxin that was lethal to Vero cells. Conclusions: Non-0157:H7 Shiga-like toxin producing E. coli are present in stools submitted for bacterial culture in a North American childhood population. Their role in childhood diarrhea warrants better definition.
Factors influencing buyers' willingness to offer price premiums for carbon credits sourced from urban forests

Marketing carbon offset credits generated by urban forest projects could help cities and local governments achieve their financial self-sufficiency and environmental sustainability goals. Understanding the value of carbon credits sourced from urban forests, and the factors that determine buyers' willingness to pay a premium for such credits could benefit cities in strategically marketing carbon credits to generate revenue. This study surveyed business organisations participating in carbon trading in order to explore the factors influencing buyers' willingness to pay for urban forest carbon credits in alternative marketing scenarios (i.e., with and without explicit recognition of purchase). Results suggest that buyers are willing to pay a premium for carbon credits sourced from urban forests and the amount of this premium was influenced by the purchasing business's ownership type, size, geographical scope of operations, and the level of importance placed on the co-benefits provided by urban trees.
Low prevalence of antibiotic-resistant gram-negative bacteria isolated from rural south-western Ugandan groundwater

The objective of this study was to determine antibiotic resistance patterns and specific resistance genes in Gram-negative enteric bacteria recovered from 42 different drinking water sources servicing 2 rural villages in south-western Uganda. These water sites were prone to contamination by both human and cattle activity. Of the 52 isolates examined, 26 carried antibiotic resistance genes with 25 being ampicillin resistant, 21 carrying the blaTEM gene, and no isolate carrying genes coding for extended-spectrum â.lactamases. Twelve isolates were tetracycline resistant and these bacteria carried between 1 and 3 different tet genes, with the tet(A) gene the most common. Six isolates carried the macrolide resistance mef(A) and/or the macrolide-lincosamide-streptogramin B resistance erm(B) genes. Four isolates carried the sul1 gene, and 4 isolates carried the sul1 and int1 genes indicating the presence of Class 1 integrons. The Ugandan isolates in this study had lower than expected carriage rates of antibiotic and multi-drug resistance genes, carriage of Class 1 integrons and lacked genes coding for extended-spectrum â.lactamases as compared to antibiotic resistance carriage in clinical African isolates.
Non-indigenous hydromedusae in California's upper San Francisco Estuary: life cycles, distribution, and potential environmental impacts*

Two species of hydromedusae, assumed to be native to the Black and Caspian Seas, were routinely collected in Suisun Slough, California, at the Suisun City Marina, during late summer and fall of 1997. Suisun Slough connects directly with Suisun Bay, part of the biologically complex and commercially important upper San Francisco Estuary, and with San Francisco Bay via San Pablo Bay. Maeotias marginata (Modeer 1791), has been previously reported (as M. inexspectata) from the Petaluma River, another tributary entering San Pablo Bay, while an as-yet undetermined species of Moerisia represents a new distributional record for this genus in the eastern Pacific. Morphologies of the adults and immature growth stages of medusae of both species are described. The polyp stages of both species were reared in the laboratory following spawning of adult medusae collected from the field. Both species are apparently representative of the robust and aggressive Black and Caspian Seas brackish water fauna, many species of which have been introduced into estuarine habitats worldwide. The potential of these planktonic predators to alter zooplankton communities and feed directly on larval and juvenile stages of threatened native and commercially valuable estuary fish species are all possible, but remain uninvestigated.
Identifying river of origin for age-0 Scaphirhynchus sturgeons in the Missouri and Mississippi rivers using fin ray microchemistry

Understanding linkages between natal and nursery habitats is critical for conservation of riverine fishes. Scaphirhynchus sturgeons inhabiting the middle Mississippi River may originate from the Missouri or Mississippi rivers, although relative importance of these recruitment sources is unknown. We characterized the relationship between water and sturgeon fin ray Sr:Ca, verified shifts in water Sr:Ca are recorded in age-0 sturgeon fin rays, and determined whether age-0 sturgeons from the Mississippi and Missouri rivers exhibited distinct fin ray Sr:Ca signatures. Fin ray Sr:Ca of laboratory-reared fish reflected transfer from water with elevated Sr:Ca to ambient water 1 day posthatch, indicating that short-term residency in environments can be detected. Nine of 30 age-0 fish captured in the middle Mississippi River were Missouri River emigrants. Four of these emigrants originated in the upper portion of the lower Missouri River (≥589 km upstream from its mouth), where water Sr:Ca is higher compared with t...
Can a King of Catalysis Spur U.K. Science to New Heights

SCIENCE POLICYLONDON-- David King, one of the world's leading physical chemists, was appointed last October to replace Sir Robert May as the U.K.'s chief scientific adviser. He describes the challenges of his new job, from addressing the issue of low salaries for British scientists to coping with a series of crises culminating in the ongoing outbreak of foot-and-mouth disease.
Eigenstate-Resolved Studies of Gas-Surface Reactivity: CH 4 ( ν 3 ) Dissociation on Ni(100)

A new experimental technique uses state-resolved infrared laser excitation to probe a polyatomic molecule's dissociative chemisorption dynamics with previously unattainable detail. Methane molecules excited to $v\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1$ of the ${\ensuremath{\nu}}_{3}$ C-H stretching vibration are up to 1600 times more reactive on a clean Ni(100) surface than are molecules in the ground vibrational state. Over a translational energy range of 27 to 54 kJ/mol, their absolute reaction probability increases from $3\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ to $6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$, which indicates that ${\ensuremath{\nu}}_{3}$ is responsible only in part for the vibrational activation reported in previous studies.
Experimental determination of the spinel peridotite to garnet peridotite inversion at 900° C and 1,000° C in the system CaO-MgO-Al 2 O 3 -SiO 2 , and at 900° C with natural garnet and olivine

Hydrothermal reversals of the univariant reaction orthopyroxene + clinopyroxene + spinel to garnet + olivine in the system CaO-MgO-Al2O3-SiO2 have been made in the range 900 °–1,000 ° C without intervention of hydrous phases. At 1,000 ° C the equilibrium is bracketed at 16.0±0.5 kbar, and, at 900 ° C, at 15.0±0.5 kbar. A flat but not well-constraineddP/dT slope is inferred. The composition of the garnet has been determined as (Ca3Al2Si3O12)0.15 (Mg3Al2Si3O12)0.85 at 900 ° C and 1,000 ° C. AdP/dT slope of 4.5±3 bars/K at 1,000 ° C, calculated from enthalpy of solution data, is within the experimental error range and agrees with the flat calculated slopes of Obata (1976) and Herzberg (1978). The large curvature of the reaction in the low-temperature range predicted by these authors is established. Hydrothermal reversal runs on a mixture of natural pyropic garnet and forsteritic olivine and their low-pressure breakdown products were made at 900 ° C. Above 12.5 kbar, garnet + olivine are stable. Below 9.5 kbar, garnet + olivine react to pyroxenes +spinel. Between these pressures, the probable stable assemblage on the bulk composition used is garnet + olivine + orthopyroxene. Thus, the peridotite transition has only been determined within a three-kbar interval. It is inferred from the experimental data that garnet peridotites occurring in amphibolite-granulite gneiss terrains could be formed by deep-crustal metamorphism; a subcrustal origin of the garnet-olivine association is not necessary. Seismic velocity increases at depths of 60–90 km in oceanic lithosphere, which have been considered by some to correspond to the onset of garnet in peridotite, are much deeper than the experimentally determined transition interval at 30–40 km at 900 ° C.
Probing spacetime foam with extragalactic sources.

Because of quantum fluctuations, spacetime is probably ``foamy'' on very small scales. We propose to detect this texture of spacetime foam by looking for halo structures in the images of distant quasars. We find that the Very Large Telescope interferometer will be on the verge of being able to probe the fabric of spacetime when it reaches its design performance. Our method also allows us to use spacetime foam physics and physics of computation to infer the existence of dark energy or matter, independent of the evidence from recent cosmological observations.
An exploration of the importance of the strategy used to identify gentrification

Urban scholars have described the importance of gentrification in major cities across the USA since the 1970s. While there is consensus that gentrification shaped social and physical aspects of neighbourhoods, scholars have yet to agree on how gentrified neighbourhoods should be identified. Owing to the lack of consensus, gentrification was measured in a variety of ways, which greatly influenced the neighbourhoods studied in previous research and potentially the findings of research that assessed the importance of gentrification for other neighbourhood outcomes. The current study contributes to this debate by applying and comparing two census-based strategies for identifying gentrified neighbourhoods with a qualitative neighbourhood selection strategy derived from The New York Times to New York City neighbourhoods for the span of years from 1980 to 2009. Results confirm that each of the strategies identified different neighbourhoods and that qualitative strategies for identifying gentrified neighbourhoods...
THE INVENTORY OF FUNCTIONAL STATUS‐FATHERS: Development and Psychometric Testing

The Inventory of Functional Status-Fathers (IFS-F) was developed to measure the extent to which men continue or increase their usual household, social and community, childcare, personal care, occupational, and educational activities, and assume infant care responsibilities during their partners' pregnancies and the postpartum period. Content validity was established at 86%. Reliability testing used a sample of 125 expectant fathers and 57 new fathers. Internal consistency reliability using average correlations for the subscale item to subscale total scores ranged from .54 to .75. Subscale to total IFS-F score correlations ranged from .31 to .61. Initial construct validity testing was accomplished by examination of subscale correlations, which ranged from -.02 to .69. The IFS-F may be used to assess the functional status of men during the childbearing period for clinical and research purposes.
Quantification of polycyclic aromatic hydrocarbons and nitro-substituted polycyclic aromatic hydrocarbons and mutagenicity testing for the characterization of ambient air particulate matter☆

Abstract As part of a study to identify mutagenic and potentially carcinogenic compounds in urban air particulate extracts, the polycyclic aromatic hydrocarbon (PAH) mixture isolated from a large sample collected in Philadelphia, PA, was characterized by liquid chromatography (LC), gas chromatography (GC), and gas chromatography-mass spectrometry (GC-MS). After isolation of the aromatic fraction from the extract using classical liquid-liquid partitioning and silica gel column chromatography, the PAH fraction was isolated by normal-phase LC. A number of the major PAH constituents were quantified by GC and LC. Quantification of the minor constituents was accomplished by further subfractionation of the PAH mixture into eight fractions based on the number of aromatic carbons in the PAH. These fractions were then characterized by GC and GC-MS. More than 100 PAH components were quantified in this sample. Approximately 40 unsubstituted PAH and 10 methyl-substituted PAH were identified based on GC retention, LC retention, fluorescence, and/or mass spectral data. Several nitro-substituted PAH were also found in the PAH fraction and the more polar fractions isolated from the original aromatic fraction.
Label-Free SERS Detection of Proteins and Bacteria Using Optical Fibers for Sensitivity Improvement

Label-free detections of certain proteins and live bacterial cells in aqueous solutions are demonstrated using surface-enhanced Raman scattering and optical fiber probes, with sensitivities order(s) of magnitude higher than those previously reported.
Reactions of chlorosilanes with formaldehyde—I chloromethoxytrichlorosilane and its decomposition

Abstract Chloromethoxytrichlorosilane, ClCH2OSiCl3, was prepared both by chlorination of methoxytrichlorosilane and by the reaction of silicon tetrachloride with formaldehyde. Chloromethoxydichlorosilane, ClCH2OSiHCl2, similarly was obtained as the product of the reaction of trichlorosilane with formaldehyldehyde. The least stable chloromethoxysilane was found to be ClCH2OSiH3, which decomposed rapidly to monochlorosilane and formaldehyde at room temperature, and the most stable was ClCH2OSiCl3, which on standing at room temperature slowly reverted to silicon tetrachloride and a non-volatile liquid, probably bis(chloromethoxy)dichlorosilane. At elevated temperature the decomposition of chloromethoxytrichlorosilane to silicon tetrachloride and formaldehyde was brought to completion by the decomposition of formaldehyde to hydrogen, carbon monoxide, and methanol. Chloromethoxytrichlorosilane readily reacted with aluminium chloride at 150° to form methylene chloride and a non-volatile product which contained alumino-chlorosilicates.
Ultrafast optical delay line using soliton propagation between a time-prism pair

Using soliton propagation between a time-prism pair, we apply time-prisms to ultrashort pulses and demonstrate an all-fiber, programmable optical delay line with a scan rate of 0.5 GHz, and a delay range of 33.0 ps.
What makes a network go round? Exploring the structure of a strong component with exponential random graph models

Abstract A strong component is a subgraph in a directed network where, following the direction of ties, all nodes in the graph are reachable from one another. Mutual reachability implies that every node in the graph is theoretically able to send materials to and/or influence every other node suggesting that strong components are amongst the more egalitarian network structures. Despite this intriguing feature, they remain understudied. Using exponential random graph models (ERGM) for directed networks, we investigate the social and structural processes underlying the generation of strong components. We illustrate our argument using a network of 301 nodes and 703 personal lending ties from Renaissance Florence. ERGM shows that our strong component arises from triadic clustering alongside an absence of higher-order star structures. We contend that these processes produce a strong component with a hierarchical , rather than an egalitarian structure: while some nodes are deeply embedded in a dense network of exchange, the involvement of others is more tenuous. More generally, we argue that such tiered core-periphery strong components will predominate in networks where the social context creates conditions for an absence of preferential attachment alongside the presence of localized closure. Although disparate social processes can give rise to hierarchical strong components linked to these two structural mechanisms, in Florence they are associated with the presence of multiple dimensions of social status and the connectedness of participants across disparate network domains.
Evaluation of Solvent Accessibility to the [Fe(4)S(4)] Binding Pocket in Native and Tyr19 Mutant High Potential Iron Proteins by (1)H-(15)N HMQC and (19)F NMR Experiments.

The solvent accessibility of Chromatium vinosum high potential iron protein (HiPIP) has been investigated by use of 1H−15N HMQC, and 19F NMR spectroscopy. These NMR experiments indicate that solven...
The Role of an Engineering Oriented Medical Research Group in Developing Improved Methods and Devices for Achieving Ventricular Defibrillation: The University of Missouri Experience

Physical scientists and engineers have played important roles in helping to expand our understanding of the factors that influence the defibrillation process and in developing improved methods and devices for achieving cardiac ventricular defibrillation. The long-term experience of one engineering oriented group, based in a clinical department of a medical school, is summarized. Emphasized are the features of a series of research defibrillators that facilitated the generation of an extensive experimental database from studies in dogs and calves, the development of the first automatic implantable defibrillator to be successfully used in dogs, and studies that furnished the rationale for the widespread use of the uniphasic truncated exponential waveform and for the increasing interest in a variety of biphasic and multiphasic waveforms. Also considered are studies concerning the scaling of the defibrillatory shock with subject size and the role of compound units, defibrillation threshold, and contour graphs in the presentation and interpretation of data.
Isopropanol oxidation by pure metal oxide catalysts: number of active surface sites and turnover frequencies

Abstract The objective of the present study was to determine the number of active surface sites and their nature, redox or acidic, for bulk metal oxide catalysts using isopropanol as a chemical probe molecule. Isopropanol oxidation activity on the following metal oxides was investigated: MgO, CaO, SrO, BaO, Y 2 O 3 , La 2 O 3 , CeO 2 , TiO 2 , ZrO 2 , HfO 2 , V 2 O 5 , Nb 2 O 5 , Ta 2 O 5 , Cr 2 O 3 , MoO 3 , WO 3 , Mn 2 O 3 , Fe 2 O 3 , Co 3 O 4 , Rh 2 O 3 , NiO, PdO, PtO, CuO, Ag 2 O, Au 2 O 3 , ZnO, Al 2 O 3 , Ga 2 O 3 , In 2 O 3 , SiO 2 , SnO 2 and Bi 2 O 3 . On average, the number of active surface sites for isopropanol dissociative adsorption on these catalysts was ∼2–4 μmol/m 2 . The number of active surface sites enabled quantification of the turnover frequency (TOF) for these catalysts. The TOF values for the various pure metal oxides were normalized at 200 °C. The TOFs of catalysts showing redox activity vary by six-orders of magnitude (10 2 to 10 −4 s −1 ). For catalyst showing acidic activity, the TOFs varied by over eight-orders of magnitude (10 1 to 10 −7 s −1 ). The reaction products from isopropanol oxidation at low conversions reflected the nature of the active surface sites, redox or acidic, on these catalysts. Redox surface sites yield acetone and acidic surface sites yield propylene. Small amounts of isopropyl ether formation are sometimes also observed via bimolecular recombination of surface isopropoxide species on acidic surface sites. All catalysts with the exception of Fe 2 O 3 and TiO 2 , exhibited extremely high selectivity to either redox or acidic products. Except for the sharp decrease in TOFs towards redox products with increasing bulk M–O heats of formation at low −Δ H f , no correlations were found between the TOFs and bulk metal oxide properties (TPR–H 2 and −Δ H f ). However, an inverse relation was found between the TOFs (redox) and the surface isopropoxide intermediate decomposition temperature at low decomposition temperatures. At moderate and high decomposition temperatures, the TOFs (redox) were almost independent of the surface isopropoxide decomposition temperature. The selectivity of the metal oxide catalysts was found to be independent of the TOFs.
The Calculation of Reliability From a Split-Plot Factorial Design

This paper treats the question, "How should one estimate the reliability of school (or classroom) means when persons are nested within schools (or classrooms)?" We begin by reviewing the use of variance components in the estimation of reliability from a randomized block (RB) design. Then we extend this rationale to the estimation of reliability (or generalizability) coefficients in a split-plot factorial (SPF) design with persons nested within schools.Through the use of variance components from the SPF design, we derive estimates of reliability for schools and for persons within schools. Then we compare the reliability for persons within schools from a SPF design with the reliability for persons from a RB design. Finally, we compare the reliability for schools from a SPF design with the reliability for school means from a RB design.
Variations in carbonyl mode intensities in inelastic electron tunneling, and multiple reflection absorption infrared spectroscopy Part I: effects due to the lead cover films for selected mono-carboxylic acids on alumina

Abstract In the first of a series of three articles, evidence for attenuation of the carbonyl vibrational mode intensity in inelastic electron tunneling spectroscopy (IETS), and multiple reflection absorption infrared spectroscopy (MRAIRS) is presented. The work may have considerable impact on the interpretation of IET and MRAIR spectra of certain polymers adsorbed on alumina of interest in the field of adhesion. For a better comparison between the two techniques, MRAIR spectra are recorded for compounds adsorbed on conventional oxidized aluminum mirror samples and on samples prepared with thin-film lead cover films to form planar aluminum/alumina/compound/lead structures similar to the tunnel junctions used for IETS. The compounds chosen for the study are all carboxylic acids, known to adsorb on alumina by coordinate bonding of the carboxylate anion in acid–base reactions. The acids contain non-bonding carbonyl groups on the carbon backbone of the molecules whose intensities are investigated. When the compounds are constrained by the above sample geometry, similar carbonyl attenuation is observed in both IETS and MRAIRS, but to varying degrees depending on the geometry of the adsorbed molecules. The effect, which disappears in MRAIR spectra for samples without the lead cover films, can be explained by consideration of the deformation of the molecules by the lead cover film, which results in steric hindrance of the carbonyl groups and a corresponding reduction in their activity in accordance with the orientational selection rules for both IETS and MRAIRS. This and further spectroscopic evidence for deformation of the molecules by the lead cover film is discussed.
Circularly Polarized Luminescence of Curium: A New Characterization of the 5f Actinide Complexes

A key distinction between the lanthanide (4f) and the actinide (5f) transition elements is the increased role of f-orbital covalent bonding in the latter. Circularly polarized luminescence (CPL) is an uncommon but powerful spectroscopy which probes the electronic structure of chiral, luminescent complexes or molecules. While there are many examples of CPL spectra for the lanthanides, this report is the first for an actinide. Two chiral, octadentate chelating ligands based on orthoamide phenol (IAM) were used to complex curium(III). While the radioactivity kept the amount of material limited to micromole amounts, spectra of the highly luminescent complexes showed significant emission peak shifts between the different complexes, consistent with ligand field effects previously observed in luminescence spectra.
Internal fertilization: adaptive value to early amniotes.

Abstract A hypothesis is presented for evolution of internal fertilization in predecessors of amniote vertebrates as a mechanism for maintaining inter-specific reproductive isolation.
Effectiveness of submersed angiosperm-epiphyte complexes on exchange of nutrients and organic carbon in littoral systems. II. Dissolved organic carbon

Abstract Refractory dissolved organic compounds, consisting mainly of fulvic acids labelled with 14C of aquatic plant origin, were added to the inlet stream water of a hardwater lake and passed through two continuously, very slowly flowing ( 3 1 24 h ) littoral systems. System I contained a natural stand of Scirpus subterminalis Torr. and System II contained Myriophyllum heterophyllum Michx. Macrophytic epiphytic were left intact. Control systems, containing similar sediments without macrophytes, received identical treatments. Dissolved organic carbon (DOC), both labelled and unlabelled, of inflow and outflow water was fractionated into several molecular weight fractions; UV absorption and fluorescence of dissolved organic matter, particulate organic carbon (POC), and major cationic concentrations were also analyzed in inflowing and outflowing water. The pathways of the labelled refractory organic carbon amendments were followed in the water, the plant foliage and roots, epiphytes, and the sediments. DOC inputs, especially of high molecular weight, were appreciably reduced in the gradual movement through the macrophyte—epiphyte complexes, although more dissolved fluorescing organic matter of > 1000 Daltons was released from the plant complexes than from control systems without macrophytes. Cationic concentrations of calcium and magnesium were reduced markedly by passage through the littoral systems; those of sodium increased slightly from the Myriophyllum community. While a major portion of the labelled refractory dissolved organic compounds moved directly through the littoral complexes, reductions were found in outflows from the Scirpus system and increases in the
Megavolt arsenic implantation into silicon

Abstract Implantations of arsenic at 11 MeV have been performed into Si(100) substrates at room and liquid nitrogen temperatures. The residual damage after annealing has been observed using Rutherford backscattering and cross-sectional transmission electron microscopy. In situ annealing is shown to be more important for room temperature implantation compared with liquid nitrogen temperature implantation. Spreading resistance has been used to determine active carrier concentrations, and the measured range of 4.4 μm agrees with Linhard-Scharff-Schi∅tt calculations. Buried interconnects with a sheet resistance of 50 Ω/▭ have been fabricated and tested.
Wavelet-based neural network with fuzzy-logic adaptivity for nuclear image restoration

A novel wavelet-based neural network with fuzzy-logic adaptivity (WNNFA) is proposed for image restoration using a nuclear medicine gamma camera based on the measured system point spread function. The objective is to restore image degradation due to photon scattering and collimator photon penetration with the gamma camera and allow improved quantitative external measurements of radionuclides in vivo. The specific clinical model proposed is the imaging of bremsstrahlung radiation using /sup 32/P and /sup 90/Y. The theoretical basis for four-channel multiresolution wavelet decomposition of the nuclear image into different subimages is developed with the objective of isolating the signal from noise. A fuzzy rule is generated to train a membership function using least mean squares to obtain an optimal balance between image restoration and the stability of the neural network, while maintaining a linear response for the camera to radioactivity dose. A multichannel modified Hopfield neural network architecture is then proposed for multichannel image restoration using the dominant signal subimages.
Water management as a cultural control tactic for the rice water weevil (Coleoptera: Curculionidae) in southwest Louisiana.

A field experiment was conducted in 1991 and repeated in 1992 to compare the use of carbofuran and field drainage as tactics for control of rice water weevil, Lissorhoptrus oryzophilus Kuschel, and to examine the effect on yield of rice (Oryza sativa L.) caused by 1- to 3-d delay in reflooding after drainage. Results showed that, although timely draining of fields significantly reduced immature weevil populations, the tactic was not always reliable nor economical. Reinfestation by rice water weevil populations after drained fields are reflooded can nullify the benefits derived from drainage. Grain yields were not affected by delayed reflooding of fields.
Combined bound-grid-factor constraints for enhancing RLT relaxations for polynomial programs

This paper studies the global optimization of polynomial programming problems using Reformulation-Linearization Technique (RLT)-based linear programming (LP) relaxations. We introduce a new class of bound-grid-factor constraints that can be judiciously used to augment the basic RLT relaxations in order to improve the quality of lower bounds and enhance the performance of global branch-and-bound algorithms. Certain theoretical properties are established that shed light on the effect of these valid inequalities in driving the discrepancies between RLT variables and their associated nonlinear products to zero. To preserve computational expediency while promoting efficiency, we propose certain concurrent and sequential cut generation routines and various grid-factor selection rules. The results indicate a significant tightening of lower bounds, which yields an overall reduction in computational effort for solving a test-bed of polynomial programming problems to global optimality in comparison with the basic RLT procedure as well as the commercial software BARON.
Social impacts of tourism on Central Florida.

Abstract The purpose of this study was to investigate Central Florida residents' perception of the social consequences and impacts of tourism. A telephone survey of 203 Central Florida households revealed that residents not only supported the current magnitude of the tourism industry, but also favored its expansion. Despite this overall positive feeling, Central Floridians identified some specific positive and negative impacts that, in their opinion, tourism had on their community. In addition, the study revealed a relationship between overall level of support for Central Florida Tourism and residents' perceptions of the consequences of tourism.
Passive Microwave Structure of Severe Tornadic Storms on 16 November 1987

Passive microwave observations using the Special Sensor Microwave/Imager (SSM/I) are presented for severe tornadic storms in the lower midwestern United States on 16 November 1987. These measurements are compared with Geostationary Operational Environmental Satellite infrared (IR) measurements for the same case. The IR observations had a classic 'V' cold feature commonly associated with severe Midwest thunderstorms. The minimum microwave brightness temperatures at 86 GHz, which primarily respond to ice scattering by larger ice particles, were located in the convective region and the warm interior of the anvil top, between the arms of the IR V feature. The interior warm region was the only portion of the entire anvil region that had high 86-GHz polarization difference temperatures. Microphysical implications of these multispectral observations are discussed. The observations suggest that there are large variations of ice microphysical characteristics spatially and vertically in the anvil region. These observations are discussed in the context of previous dynamical and microphysical hypotheses on the IR V feature.
Infant feeding practices: Perceptions of Native American mothers and health paraprofessionals:

Objective: To ascertain infant feeding practices and to explore the feasibility of an in-home feeding intervention with Native American Indian (NAI) mothers in six Native American communities in the United States (US).Design: Qualitative focus group study.Setting: Six Native American communities in the Midwest region of the United States.Method: Fourteen NAI health paraprofessionals and 42 NAI mothers took part in 12 focus groups that were conducted by a facilitator, according to a semi-structured topic guide. Focus group data were supplemented with demographic data.Results: For the NAI health paraprofessionals, four major themes emerged: (1) maternal feeding practices for their infants; (2) special considerations when working with the NAI population; (3) sources of advice for NAI mothers; and (4) tailoring a feeding intervention to NAI mothers of infants. For the NAI mothers, four major themes emerged: (1) maternal feeding practices for their infants; (2) expectations about an in-home intervention and ho...
Increased receptor binding of low-density lipoprotein from individuals consuming a high-carbohydrate, low-saturated-fat diet.

The substitution of saturated fat by complex carbohydrate, according to current dietary recommendations, results in a decrease of plasma and low-density lipoprotein (LDL) cholesterol levels. To determine whether this decrease might result from structural and thus functional changes in LDL particles, the binding internalization and degradation of 125I-LDL were measured using TR715-19 cells, a mutant CHO line into which has been transfected the human LDL receptor, and in which measurements of binding are highly reproducible. Eleven nondiabetic subjects (35 ± 4 years, 27% ± 3% body fat) were studied after they had completed 3 to 5 weeks on each of two isocaloric diets, with one diet containing 42% fat (21% saturated) 43% carbohydrate, 15% protein, and 560 mg cholesterol/d and the other containing 21% fat (6% saturated), 65% carbohydrate, 14% protein, and 524 mg cholesterol/d. LDL cholesterol levels decreased from 125 ± 6 to 108 ± 5 mg/dL (P < .01) on the high-carbohydrate diet. There was an increase in the binding affinity of LDL (Kd, 6.6 ± 2.6 v 7.3 ± 2.7 μg/mL ± SD; P < .02), and internalization (P < .10) and degradation (P < .05) were also higher. The data suggest that decreasing dietary saturated fat may cause alterations in LDL composition that result in increased receptor clearance; this may partially explain the LDL-decreasing effect of this dietary change.
Oxygenation of Human Tumor Xenografts in Nude Mice by a Perfluorochemical Emulsion and Carbogen Breathing

Human solid tumors (prostate carcinomas PC-3 and DU-145, breast carcinoma MX-1, cervical carcinoma ME-180, small cell lung carcinoma SW2, and glioblastoma T98G) were grown as xenografts in nude mice. Using the Eppendorf pO2 histograph microelectrode system, the oxygen profiles of the tumors were determined while the animals breathed air or carbogen (95% O2/5% CO2), and after administration of the perfluorochemical emulsion Oxygent-CA (8 ml/kg) under air breathing and carbogen breathing conditions. Under normal air breathing with or without Oxygent-CA administration the mean oxygen tensions were between 4.9 and 9.3 mmHg and each tumor had severely hypoxic regions where the pO2 was less than 5 mmHg. The severely hypoxic regions comprised 41-71% of the oxygen tension measurements under normal air breathing conditions. Carbogen breathing alone increased the mean oxygen tensions to 10.9-23.9 mmHg. Administration of Oxygent-CA and carbogen breathing increased the mean oxygen tensions over the levels of carbogen...
Assessing and improving service performancefor maximum impact: insights from a two‐decade‐long research journey

Starting in 1983, and sponsored by the Marketing Science Institute (MSI), the service research journey has consisted of multiple research phases that have covered a variety of sectors, employed both qualitative and quantitative research techniques and included interviews with managers, employees and customers of dozens of organizations. The focus of this paper has been on understanding, measuring and improving service quality. The research has produced concepts, models and tools, which are now widely used for evaluating service quality in the commercial sector.
Implementation of liquid chromatography/mass spectrometry into the clinical laboratory.

Abstract Background For certain clinical chemistry and toxicology analytes, liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS) offers significant advantages over traditional testing by immunoassay. Methods Published reports comparing the performance of immunoassays against LC–MS/MS were reviewed. The tested analytes include testosterone, estradiol, thyroid hormones, vitamin D, immunosuppressants, steroids for newborn screening programs, and clinical and forensic toxicology. Results While immunoassays are widely used in the clinical laboratory, the analytical sensitivity and specificity are inferior for many of the analytes tested in routine clinical laboratories. Moreover, LC–MS/MS can be multiplexed for high testing throughput and multiple analyte detection. The disadvantages of LC-MS/MS include the absence of Food and Drug Administration (FDA) and Conformite Europeenne (CE) Mark approved tests, the high cost of analytical instrumentation, and the technical expertise needed to operate and maintain analyzers. Conclusions The implementation of LC–MS/MS will increase in the next few years as this technology continues to improve and the advantages become more well known.
Tranquility and preference as affective qualities of natural environments

Abstract Independent groups rated 66 color slides of natural settings for the target variables tranquility and preference and for four descriptor variables. Tranquility and preference ratings were strongly correlated across all settings (r = 0.91). Nevertheless, it was possible to distinguish the two constructs both in terms of mean differences within specific categories of natural settings and in terms of their relationships with descriptor variables. Tranquility was rated higher than preference within the categories of Field-Forest, Large Bodies of Water, and Misty Mountains, while preference was rated higher in the category of Rushing Water. As predicted, ratings of focus (the extent to which the setting contains strong focal points) were more strongly correlated with preference ratings than with tranquility ratings. The same pattern held within all four of seven categories of natural settings in which tranquility and preference were not redundant (r ≤ 0·83). It appears that tranquility and preference are related but discriminable constructs with their discriminability more pronounced in some environmental categories than in others.
Rat pulmonary lipoxygenase: dioxygenase activity and role in xenobiotic metabolism.

Abstract 1. 1. Dioxygenase activity and the ability of pregnant rat lung lipoxygenase to oxidize xenobiotics were examined in vitro under a variety of experimental conditions. 2. 2. More than 90% of the dioxygenase activity towards linoleic acid in the lung homogenate was found to be associated with the cytosolic fraction. The cytosolic enzyme exhibited pH optima at 6.5 and 9.5, the activity being two-fold greater at pH 9.5. To observe maximal dioxygenase activity (about 0.7 μmol of 13-hydroperoxylinoleic acid formed/min per mg protein) at pH 9.5, the presence of 6.0 mM linoleic acid was required. 3. 3. Benzidine oxidation occurred at maximal rate of pH 6.5 when the reaction medium contained 1.0 mM benzidine and 13.5 mM linoleic acid. All eight xenobiotics tested were oxidized at significant rates by the lung cytosolic lipoxygenase. 4. 4. Both dioxygenase activity and benzidine oxidation were inhibited by the inhibitors of lipoxygenase, viz. nordihydroguaiaretic acid, BHT, caffeic acid, esculetin, and gossypol, in a concentration-dependent manner. 5. 5. The results suggest that oxidation of xenobiotics by lipoxygenase may be an important pathway of metabolism in the mammalian lung.
Can Differences in Host Behavior Drive Patterns of Disease Prevalence in Tadpoles

Differences in host behavior and resistance to disease can influence the outcome of host-pathogen interactions. We capitalized on the variation in aggregation behavior of Fowler's toads (Anaxyrus [ = Bufo] fowleri) and grey treefrogs (Hyla versicolor) tadpoles and tested for differences in transmission of Batrachochytrium dendrobatidis (Bd) and host-specific fitness consequences (i.e., life history traits that imply fitness) of infection in single-species amphibian mesocosms. On average, A. fowleri mesocosms supported higher Bd prevalences and infection intensities relative to H. versicolor mesocosms. Higher Bd prevalence in A. fowleri mesocosms may result, in part, from higher intraspecific transmission due to the aggregation of tadpoles raised in Bd treatments. We also found that, independent of species, tadpoles raised in the presence of Bd were smaller and less developed than tadpoles raised in disease-free conditions. Our results indicate that aggregation behavior might increase Bd prevalence and that A. fowleri tadpoles carry heavier infections relative to H. versicolor tadpoles. However, our results demonstrate that Bd appears to negatively impact larval growth and developmental rates of A. fowleri and H. versicolor similarly, even in the absence of high Bd prevalence.
Taking Responsibility Sex Differences in Reporting Dating Violence

This study made use of a survey mailing to examine sex differences in reporting dating violence among college students. Respondents were surveyed regarding their frequency of inflicting and sustaining aggression in their dating relationships. Male and female responses to questions regarding who was responsible for violent acts were compared. The findings suggest that males are less likely than females to take responsibility for violence in a relationship and more likely to place blame on their partner. Males were also more likely to indicate the use of alcohol or drugs during violent episodes. Implications for future research are discussed.
Some visual displays of two‐by‐two data: Predicting later violent behavior

A two-by-two table effectively presents the relationship between a predictor and an outcome. Using fewer cells in the table focuses the reader's attention on the contingent relationship.
Haemophilus haemolyticus Isolates Causing Clinical Disease

We report seven cases of Haemophilus haemolyticus invasive disease detected in the United States, which were previously misidentified as nontypeable Haemophilus influenzae. All cases had different symptoms and presentations. Our study suggests that a testing scheme that includes reliable PCR assays and standard microbiological methods should be used in order to improve H. haemolyticus identification.
Critical behavior of the paramagnetic line width in RbMnF3

Abstract The EPR line whidth has been measured in RbMnF 3 near T N at 9.2 GHz and 24.4 GHz. The EPR line narrows as T N is approached. The temperature dependence of the line width is suppressed as the Larmor frequency is increased.
Induction of sister-chromatid exchanges in L1210 leukemia cells by new antitumor 2-haloethyl(methylsulfonyl) methanesulfonate compounds

The antitumor 2-halo(chloro, bromo, and fluoro)-ethyl(methylsulfonyl) methanesulfonates, ethyl(methylsulfonyl) methanesulfonate, and chlorozotocin, a 2-chloroethylnitrosourea, were evaluated for their potential to induce SCEs in L1210 cells. The results indicate that all the compounds induced approximately 2-fold or greater increases in SCEs in a dose-related manner. 2-Chloroethyl(methylsulfonyl) methanesulfonate, a DNA-interacting agent and a drug selected for clinical trials, exhibited the highest SCE increase in these cells.