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Iowa State University

Selected Works

1991

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Hepatic Microsomal N-Hydroxylation Of Aniline And 4-Chloroaniline By Rainbow Trout (Onchorhyncus Mykiss), Steven P. Bradbury, J. M. Dady, A. D. Hoffman, M. M. Voit, D. L. Olson Dec 1991

Hepatic Microsomal N-Hydroxylation Of Aniline And 4-Chloroaniline By Rainbow Trout (Onchorhyncus Mykiss), Steven P. Bradbury, J. M. Dady, A. D. Hoffman, M. M. Voit, D. L. Olson

Steven P. Bradbury

N-Hydroxylation of aniline and 4-chloroaniline was quantified in rainbow trout microsomal preparations using h.p.l.c.-liquid scintillation methods. Radioactive phenylhydroxylamine and 4-chlorophenylhydroxylamine metabolites were identified by co-elution with non-labelled standards. The method provided resolution of metabolite standards, and quantification of both N-hydroxylated metabolites was achieved without derivatization. The maximum velocities at 25 degrees C were 33.8 +/- 1.40 and 22.0 +/- 0.98 pmol/min per mg for aniline and 4-chloroaniline N-hydroxylation, respectively. The Km values were 1.0 +/- 0.11 and 0.8 +/- 0.11 mM for aniline and 4-chloroaniline N-hydroxylation, respectively. These activities were not induced by treatment of the trout with Aroclor 1254 …

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Comparison Of A Quantitative Microtiter Method, A Quantitative Automated Method, And The Plate-Count Method For Determining Microbial Complement Resistance, Margie D. Lee, Richard E. Wooley, John Brown, Kathy R. Spears, Lisa K. Nolan, Emmett B. Shotts Jr. Dec 1991

Comparison Of A Quantitative Microtiter Method, A Quantitative Automated Method, And The Plate-Count Method For Determining Microbial Complement Resistance, Margie D. Lee, Richard E. Wooley, John Brown, Kathy R. Spears, Lisa K. Nolan, Emmett B. Shotts Jr.

Lisa K. Nolan

A quantitative microtiter method for determining the degree of complement resistance or sensitivity of microorganisms is described. The microtiter method is compared with a quantitative automated system and the standard plate-count technique. Data were accumulated from 30 avian Escherichia coli isolates incubated at 35 C with either chicken plasma or heat-inactivated chicken plasma. Analysis of data generated by the automated system and plate-count techniques resulted in a classification of the microorganisms into three groups: those sensitive to the action of complement; those of intermediate sensitivity to the action of complement; and those resistant to the action of complement. Although the …

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Comparison Of Chicken Plasma And Guinea Pig Serum In A Quantitative Microtiter Method Of Determining Microbial Complement Resistance, Richard E. Wooley, John Brown, Kathy R. Spears, Lisa K. Nolan Dec 1991

Comparison Of Chicken Plasma And Guinea Pig Serum In A Quantitative Microtiter Method Of Determining Microbial Complement Resistance, Richard E. Wooley, John Brown, Kathy R. Spears, Lisa K. Nolan

Lisa K. Nolan

Y. A quantitative microtiter method using chicken plasma is described for determining the degree of complement resistance or sensitivity of avian Escherichia coli isolates. Results obtained with the microtiter method using chicken plasma were compared with results obtained using commercially available standardized guinea pig serum as the source of complement. The test organisms consisted of five isolates of E. coli isolated from chickens. Three isolates were from flocks with colisepticemia; one was from a flock with omphalitis; and one isolate was a non-pathogenic control. Data were accumulated from the five avian E. coli isolates incubated at 35 C with either …

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Bronchiolar Metaplasia And Ulex Europaeus Agglutinin I (Uea-I) Affinity In Mycoplasma Hyopneumoniae-Infected Lungs Of Six Pigs, Mark R. Ackermann, M. C. Debey, B. M. Debey Nov 1991

Bronchiolar Metaplasia And Ulex Europaeus Agglutinin I (Uea-I) Affinity In Mycoplasma Hyopneumoniae-Infected Lungs Of Six Pigs, Mark R. Ackermann, M. C. Debey, B. M. Debey

Mark R. Ackermann

Mycoplasma hyopneumoniae adheres to the cilia and apical plasma membrane of cells that line the trachea, bronchi, and bron ch ioles. Colonization result s in ciliostasis and peribronchial and peribronchi olar nod ular aggregates of lymphocytes and plasma cells.">Altho ugh adhesion-receptor interaction s between the organism and respiratory epithelial cells have been examined, little attention has been given to the morphologic and phenotypic changes that may occur in cells lining bron chioles during infection. In this study, we describe morphologic cha nges and differenc es in lectin staining patt ern s in the bron chi oles from lungs of …

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Detection Of Unresolved Target Tracks In Infrared Imagery, Sarah A. Rajala, Loren W. Nolte, James V. Aanstoos Nov 1991

Detection Of Unresolved Target Tracks In Infrared Imagery, Sarah A. Rajala, Loren W. Nolte, James V. Aanstoos

Sarah A. Rajala

Two methods for detecting dim, unresolved target tracks in infrared imagery are presented. Detecting such targets in a sequence of noisy images is very challenging from the standpoint of algorithm design as well as detection performance evaluation. Since the signal-to-noise ratio per pixel is very low (a dim target) and the target is unresolved (of spatial extent less than a pixel), one must rely on integration over target tracks which span over many image frames. In addition, since there is a large amount of uncertainty as to the pattern and location of target tracks, good algorithms must consider a large …

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An Analytical Representation Of The Lowest Potential Energy Surface For The Reaction O(3 P)+Hcl (X  1Σ+)→Oh(X  2Π)+Cl(2 P), H. Koizumi, George C. Schatz, Mark S. Gordon Nov 1991

An Analytical Representation Of The Lowest Potential Energy Surface For The Reaction O(3 P)+Hcl (X  1Σ+)→Oh(X  2Π)+Cl(2 P), H. Koizumi, George C. Schatz, Mark S. Gordon

Mark S. Gordon

We present a new analytical representation of the lowest 3 A‘ energy surface for the reaction O(3 P)+HCl(X  1Σ+)→OH(X  2Π)+Cl(2 P). This surface is derived by fitting a b i n i t i o calculations, and adjustments are made to the barrier height so that rate constants derived from accurate quantum scattering calculations match the room temperature thermal rate constants. Contributions to thermal and state resolved rate constants arising from reaction on the lowest 3 A’surface are also considered. Comparisons of thermal and state resolved rate constants with experiment are good except at high temperature where the 3 A’ …

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Swine Responses To Constant And Modified Diurnal Cyclic Temperatures, Hongwei Xin, James A. Deshazer Nov 1991

Swine Responses To Constant And Modified Diurnal Cyclic Temperatures, Hongwei Xin, James A. Deshazer

Hongwei Xin

Ad libitum fed and individually penned crossbred gilts (39 ± 2 kg) were exposed to a constant air temperature of 30.8*" C (CON) and equal-mean diurnal cyclic temperatures cycling from 26° to 33*^ C (RPK) and from 23.4° to 40° C (RNT). Fluorescent lighting with an intensity of 800 to 1100 L/m/m2 was provided from 0600 h to 2100 h. Measurements of feed intake, heat loss rates, water usage, growth, and ingestion behavior were made for a five-day period and replicated six times. Daily average heat loss rates, water usage, and feed conversion of the RPK and RNT pigs could …

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Stimulation Of Pheromone Biosynthesis In The Moth Helicoverpa Zea: Action Of A Brain Hormone On Pheromone Glands Involves Ca2+ And Camp As Second Messengers, Russell A. Jurenka, Emmanuelle Jacquin, Wendell L. Roelofs Oct 1991

Stimulation Of Pheromone Biosynthesis In The Moth Helicoverpa Zea: Action Of A Brain Hormone On Pheromone Glands Involves Ca2+ And Camp As Second Messengers, Russell A. Jurenka, Emmanuelle Jacquin, Wendell L. Roelofs

Russell A. Jurenka

Isolated abdomen and pheromone gland bioassays were utilized to determine the physiological action of the pheromone-biosynthesis-activating neuropeptide (PBAN) in the corn earworm moth Helicoverpa (= Heliothis) zea. An isolated pheromone gland bioassay showed that synthetic PBAN was active at 0.02 pmol, with maximal activity occurring at 0.5 pmol and 60 min of incubation. Second-messenger studies demonstrated that extracellular Ca2+ is necessary for PBAN activity on isolated pheromone glands. The Ca2+ ionophore A23187 stimulated pheromone biosynthesis alone, whereas the Ca2+ channel blockers La3+ and Mn2+ inhibited PBAN activity. However, the organic Ca2+ channel blockers verapamil and nifedipine did not inhibit PBAN …

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The Conformational Potential Energy Surface Of Glycine: A Theoretical Study, Jan H. Jensen, Mark S. Gordon Oct 1991

The Conformational Potential Energy Surface Of Glycine: A Theoretical Study, Jan H. Jensen, Mark S. Gordon

Mark S. Gordon

The conformational potential energy surface of nonionized glycine has been studied by using ab initio (6-310*, ST0-20) and semiempirical (AM1, PM3) methods. The MP2/6-31G*/ /RHF/6-310* potential energy surface was then used to calculate the Boltzmann equilibrium distribution and kinetics of conformational interconversion at various temperatures. The results of this study are compared to previous computational and experimental investigations of gas-phase glycine.

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Structures And Bonding Of Group Iv Sulfur And Oxygen Propellane Derivatives, Kiet A. Nguyen, Marhsall T. Carroll, Mark S. Gordon Oct 1991

Structures And Bonding Of Group Iv Sulfur And Oxygen Propellane Derivatives, Kiet A. Nguyen, Marhsall T. Carroll, Mark S. Gordon

Mark S. Gordon

The RHF, ROHF, and GVB structures and energetics of group IV 2,4,5-trioxa[l.l.l]metallapropellanes, 2,4,5- trithia [ l.l.l]metallapropellanes, and their bicyclopentane analogues have been determined from ab initio molecular orbital theory by using both the 6-31G(d) basis set for all-electron calculations and the valence basis set with effective core potentials (ECP) developed by Stevens, Basch, and Krauss. Although they have extremely short bridgehead distances, these species possess fairly large natural orbital occupation numbers in the lowest unoccupied molecular orbitals, indicating significant diradical character. Structures and other properties determined by ECP calculations are in good agreement with the 6-31 G(d) all-electron calculations.

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Experimental Model Of Atrophic Rhinitis In Gnotobiotic Pigs, Mark R. Ackermann, R. B. Rimler, J. R. Thurston Oct 1991

Experimental Model Of Atrophic Rhinitis In Gnotobiotic Pigs, Mark R. Ackermann, R. B. Rimler, J. R. Thurston

Mark R. Ackermann

To study the pathogenesis of atrophic rhinitis, gnotobiotic pigs (n = 6) were inoculated intranasally with a sterile sonicate of a toxigenic strain of Bordetella bronchiseptica (0.16 mg of protein per ml) at 5 days of age, and they were then inoculated intranasally with 1 ml (5,250 CFU/ml) of a live, toxigenic strain of Pasteurella multocida at 7 days of age. Pigs were necropsied at 2, 5, 9, 14, 21, and 28 days postinoculation; those pigs necropsied after 5 days had developed turbinate atrophy. Other gnotobiotic pigs received the following inoculation protocols: (i) a sterile sonicate of a nontoxigenic strain …

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First-Principles Study Of Phase Stability In Cu-Zn Substitutional Alloys, P. E. A. Turchi, M. Sluiter, F. J. Pinski, Duane D. Johnson, D. M. Nicholson, G. M. Stocks, J. B. Staunton Sep 1991

First-Principles Study Of Phase Stability In Cu-Zn Substitutional Alloys, P. E. A. Turchi, M. Sluiter, F. J. Pinski, Duane D. Johnson, D. M. Nicholson, G. M. Stocks, J. B. Staunton

Duane D. Johnson

A parameter-free approach to phase stability in Cu-Zn substitutional alloys is shown to describe order-disorder phenomena and structural transformations with remarkable accuracy. The method is based on a multiple-scattering description of the electronic structure properties of the random alloy. Configurational order is treated within the generalized perturbation method and the concentration-functional theory. Thermodynamical properties of α and β brasses are derived from the cluster variation method. This advanced scheme is of general validity and is expected to yield similarly accurate results for other Hume-Rothery alloys.

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Predicted Enthalpies Of Formation For Methyl-Substituted Silaethylenes And Disilenes, Jerry A. Boatz, Mark S. Gordon Sep 1991

Predicted Enthalpies Of Formation For Methyl-Substituted Silaethylenes And Disilenes, Jerry A. Boatz, Mark S. Gordon

Mark S. Gordon

Enthalpies of formation of the methyl-substituted silaethylenes (CH3).H2_,Si=CH2 (n = 1, 2) and disilenes (CH3),.H~i=Si(CH3),H:~-m (n, m = Q-2) are predicted by using isodesmic reactions which relate the compound of interest to the parent silaethylene (H2Si=CH2) or disilene (H~i=SiH2), for which accurate enthalpies of formation have recently been determined. In turn, the enthalpies of formation of these methyl-substituted compounds are used in conjunction with homodesmic reactions to reevaluate the enthalpies of formation of the silicon-substituted cyclobutenes C.Si4-0H6 (n = Q-4).

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Stabilization Of Β Positive Charge By Silicon, Germanium, Or Tin, Kiet A. Nguyen, Mark S. Gordon, Gen-Tai Wang, Joseph B. Lambert Aug 1991

Stabilization Of Β Positive Charge By Silicon, Germanium, Or Tin, Kiet A. Nguyen, Mark S. Gordon, Gen-Tai Wang, Joseph B. Lambert

Mark S. Gordon

Ab initio molecular orbital theory is used to study the β effect of carbon, silicon, germanium, or tin on the carbenium ions in H2R'MCH2CHR+ (R' = H; R = H, CH3). The relative stabilization energies of carbenium ions provided by M (M = C, Si, Ge, Sn) were determined by calculating the energy change in an isodesmic reaction using MP2/3-21G(d) (at SCF /3-21G* geometries) and MP2/6-31G(d) (at SCF /6- 31G(d) geometries) wave functions. The magnitude of the β effect is predicted to increase in the order C < Si < Ge < Sn. For R = H, the nonvertical cyclic structure is favored for the cations, whereas methyl substitution appears to stabilize the vertical acyclic arrangement.

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Ab Initio Study Of Some Methylene And Silylene Insertion Reactions, David R. Gano, Mark S. Gordon, Jerry A. Boatz Aug 1991

Ab Initio Study Of Some Methylene And Silylene Insertion Reactions, David R. Gano, Mark S. Gordon, Jerry A. Boatz

Mark S. Gordon

The theoretical barriers and reaction energetics have been determined, using ab initio calculations at the MP4/6-3IG(d) level, with 3-2IG* geometries, for the insertions of methylene and silylene into the X-Y bonds of ethane, methylsilane, disilane, and cyclopropane and into the X-H bonds of disilane and ethane. A correlation was observed between barrier heights and lengths of substrate bonds. The largest barriers were observed for methylene and silylene inserting into the C-C bonds of ethane. The barriers became successively lower for the C-Si and Si-Si bonds. Steric interactions thus appear to be a major factor in determining barrier heights. The observed …

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Nature Of The Si-N Bond In Silatranes, Mark S. Gordon, Marshall T. Carroll, Jan H. Jensen, Larry P. Davis, Larry W. Burggraf, R. Martin Guidry Aug 1991

Nature Of The Si-N Bond In Silatranes, Mark S. Gordon, Marshall T. Carroll, Jan H. Jensen, Larry P. Davis, Larry W. Burggraf, R. Martin Guidry

Mark S. Gordon

Both ab initio and semiempirical calculations are used to investigate the structure and bonding in substituted silatranes. In agreement with gas-phase experiments, which fmd Si-N distances that are 0.25-0.35 A longer than those in the crystal phase, the Si-N distance (for example, in methylsilatrane) is predicted to be much larger than that observed in the crystal. Nonetheless, a bond critical point is found between Si and N, suggesting the existence of an Si-N bond in these compounds. It is found that the energy cost for constraining the Si-N distance in hydroxysilatrane to a value similar to that observed in the …

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Three-Point Correlations In Driven Diffusive Systems With Ising Symmetry, Beate Schmittmann, R. K. P. Zia Jul 1991

Three-Point Correlations In Driven Diffusive Systems With Ising Symmetry, Beate Schmittmann, R. K. P. Zia

Beate Schmittmann

For equilibrium systems with Ising symmetry, the three-point correlation function is always zero above criticality. When a lattice-gas version of this system is driven to a nonequilibrium steady state, this correlation becomes nontrivial. Its dominant large-scale behavior is found to be a consequence of both the manifest breaking of Ising symmetry by the driving force and the more subtle violation of the fluctuation-dissipation theorem.

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Systematic Survey Of Cyclic Silicon-Oxygen Compounds, Michael W. Schmidt, Kiet A. Nguyen, Mark S. Gordon, John A. Montgomery Jr. Jul 1991

Systematic Survey Of Cyclic Silicon-Oxygen Compounds, Michael W. Schmidt, Kiet A. Nguyen, Mark S. Gordon, John A. Montgomery Jr.

Mark S. Gordon

Compounds with 0, 1, 2, or 3 oxygen atoms bridging 2 silicon atoms are investigated by ab initio calculations. Two such series of compounds, with and without a formal central Si-Si bond, are considered. The triplet states of the former set are also examined. For some of these compounds, the present calculations represent the first time they have been examined at a sufficiently rigorous level of theory. For the compounds that are formally bonded, this level is two configuration SCF (TCSCF) for singlets and ROHF for triplet states, using split valence polarized basis sets. The main result is that no …

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A Theoretical Study Of Some Reactions Of Hcsi-, Michael W. Schmidt, Mark S. Gordon Jul 1991

A Theoretical Study Of Some Reactions Of Hcsi-, Michael W. Schmidt, Mark S. Gordon

Mark S. Gordon

The ions HCSi- and H2CSiH- produced in recent flowing afterglow experiments are characterized structurally. Reactivity of the former ion with four molecules (C02, OCS, CS2, S02) is examined. Three of these species react in a sequence of intermediates of cyclic followed by acyclic structures, before reaching the final products.

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Principal Resonance Contributors To High-Valent, Transition-Metal Alkylidene Complexes, Thomas R. Cundiari, Mark S. Gordon Jul 1991

Principal Resonance Contributors To High-Valent, Transition-Metal Alkylidene Complexes, Thomas R. Cundiari, Mark S. Gordon

Mark S. Gordon

The results of ab initio calculations are reported for prototypical high-valent, alkylidene complexes. Stationary points on each potential energy surface are characterized and compared to experimental information where available; as long as a suitably flexible valence basis set is used, good agreement between theoretically calculated and experimentally determined geometries is obtained. The complexes of interest include group IVB (Ti, Zr and Hf) and group VB (Nb and Ta) alkylidenes with hydride ligands as well as models for the four-coordinate, olefin metathesis catalysts (Mo-, W-, and Re-alkylidenes) which have been recently synthesized and characterized. In light of the fact that much …

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Colonization Of The Pharyngeal Tonsil And Respiratory Tract Of The Gnotobiotic Pig By A Toxigenic Strain Of Pasteurella Multocida Type D, Mark R. Ackermann, N. F. Cheville, J. E. Gallagher Jul 1991

Colonization Of The Pharyngeal Tonsil And Respiratory Tract Of The Gnotobiotic Pig By A Toxigenic Strain Of Pasteurella Multocida Type D, Mark R. Ackermann, N. F. Cheville, J. E. Gallagher

Mark R. Ackermann

Seven-day-old gnotobiotic pigs were inoculated intranasally with Pasteurella multocida and euthanatized 2, 5, 9, and 14 days after inoculation. Tissues from the oropharynx and respiratory tract of pigs were cultured quantitatively and analyzed microscopically. Pigs remained afebrile and alert, except one that died of acute fibrinopurulent pneumonia. Pasteurella multocida was isolated in greatest numbers from the pharyngeal tonsils, but only in low numbers from turbinate, trachea, lung, spleen, and liver. Significant histologic changes were limited to the tonsil. Infected pigs developed mild tonsillitis with lymphocytic hyperplasia, and accumulation of cell debris and bacteria in crypts. Capsular antigens of P. multocida, …

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Control Of Salmonella On Beef Tissue Surfaces In A Model System By Pre- And Post-Evisceration Washing And Sanitizing, With And Without Spray Chilling, James S. Dickson, Maynard E. Anderson Jul 1991

Control Of Salmonella On Beef Tissue Surfaces In A Model System By Pre- And Post-Evisceration Washing And Sanitizing, With And Without Spray Chilling, James S. Dickson, Maynard E. Anderson

James S. Dickson

Beef tissue was inoculated with a nalidixic acid resistant strain of Salmonella California and processed under conditions simulating pre- and post-evisceration carcass washing and sanitizing. These treatments, using distilled water to wash and 2% acetic acid to sanitize, reduced the population of salmonellae by as much as 2-log10 cycles when compared to samples which were washed only in distilled water. Increasing the acid temperature to 55°C reduced the bacterial populations further. Spray chilling, when used in series with the pre- and post-evisceration treatments, apparently resulted in recovery of some injured Salmonella.

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Finger Formation In A Driven Diffusive System, D. H. Boal, Beate Schmittmann, R. K. P. Zia May 1991

Finger Formation In A Driven Diffusive System, D. H. Boal, Beate Schmittmann, R. K. P. Zia

Beate Schmittmann

A driven diffusive lattice gas is studied in a rectangular geometry: particles are fed in at one side and extracted at the other, after being swept through the system by a uniform driving field. Being periodic in the transverse direction, the lattice lies on the surface of a cylinder. The resulting nonequilibrium steady state depends strongly on this choice of boundary conditions. Both Monte Carlo and analytic techniques are employed to investigate the structure of typical configurations, the density profile, the steady-state current, and the nearest-neighbor correlations. As the temperature is lowered in a finite system, the simulations indicate a …

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Lectin Histochemistry Of Trachea And Lung Of Healthy Turkeys (Meleagris Gallopavo) And Turkeys With Pneumonia, Mark R. Ackermann, N. F. Cheville, P. G. Detilleux May 1991

Lectin Histochemistry Of Trachea And Lung Of Healthy Turkeys (Meleagris Gallopavo) And Turkeys With Pneumonia, Mark R. Ackermann, N. F. Cheville, P. G. Detilleux

Mark R. Ackermann

Thirteen lectins were used to characterize lectin-binding specificity of glycoconjugates on sections of formalin-fixed lung and trachea from seven normal turkeys, two turkeys with acute pneumonia, and two turkeys with chronic pneumonia. Neuraminidase was used to digest sialic acid residues. One N-acetylgalactosamine-binding lectin and two N-acetylgalactosamine/galactose-binding lectins stained the apical membrane and cytoplasm of multifocal cells that lined air atria and hyperplastic granular cells. Other lectins in these groups stained ciliated cells of the trachea and bronchi and air capillary epithelial cells. Sialic acid residues were on apical surfaces of ciliated and nonciliated tracheal and bronchial lining cells, air capillary …

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A New Twist On Pseudorotation, Theresa L. Windus, Mark S. Gordon, Larry W. Burggraf, Larry P. Davis May 1991

A New Twist On Pseudorotation, Theresa L. Windus, Mark S. Gordon, Larry W. Burggraf, Larry P. Davis

Mark S. Gordon

For pentacoordinated structures in a trigonal bipyramidal ar· rangement, Berry1 proposed a "pseudorotation" mechanism whereby two such isomers can interconvert through a tetragonal transition state (TS). This Berry pseudorotation mechanism was demonstrated explicitly for SiH5- by following the MP22/6· 31G(d)3 minimum energy path4 (MEP).

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Thermodynamic And Structural Properties Of [001] Twist Boundaries In Gold, R. Najafabadi, D. J. Srolovitz, Richard Alan Lesar May 1991

Thermodynamic And Structural Properties Of [001] Twist Boundaries In Gold, R. Najafabadi, D. J. Srolovitz, Richard Alan Lesar

Richard Alan Lesar

We have employed the Local Harmonic (LH) model and the Embedded Atom Method (EAM) to examine the structural and thermodynamic properties of a series of twelve [001] twist boundaries in gold for temperatures between 0 K and 700 K. For the majority of the grain boundary misorientations, metastable structures were observed with grain boundary energies that were typically less than 0.1% larger than the stable structures. Four of the twelve grain boundaries underwent first order structural phase transitions as seen by the crossing of the free energy versus temperature curves for the competing structures. Relatively small cusps or inflections in …

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Immunity Induced In Rats Vaccinated With Toxoid Prepared From Heat-Labile Toxin Produced By Pasteurella Multocida Serogroup D, J. R. Thurston, R. B. Rimler, Mark R. Ackermann, N. F. Cheville, J. M. Sacks Apr 1991

Immunity Induced In Rats Vaccinated With Toxoid Prepared From Heat-Labile Toxin Produced By Pasteurella Multocida Serogroup D, J. R. Thurston, R. B. Rimler, Mark R. Ackermann, N. F. Cheville, J. M. Sacks

Mark R. Ackermann

Rats were vaccinated with a toxoid (D-toxoid) prepared from purified heat-labile toxin (D-toxin) produced by Pasteurella multocida serogroup D. Vaccination of rats with D-toxoid prevented death and other effects of D-toxin (hepatic necrosis, development of elevated leukocyte counts, lymphopenia, neutrophilia, and elevated complement titers) that occurred in phosphate buffered saline (PBS)-vaccinated control rats.

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Ferrous Fumarate Fortification Of A Chocolate Drink Powder, Richard F. Hurrell, Manju B. Reddy, Sandra A. Dassenko, James D. Cook, David Shepherd Mar 1991

Ferrous Fumarate Fortification Of A Chocolate Drink Powder, Richard F. Hurrell, Manju B. Reddy, Sandra A. Dassenko, James D. Cook, David Shepherd

Manju B. Reddy

An evaluation was made into the usefulness of ferrous fumarate as an iron fortificant for an experimental chocolate drink powder targetted to children and adolescents. Organoleptically ferrous fumarate was acceptable when the chocolate drink powder was reconstituted in milk or water that was heated to < 80". Unacceptable colour changes occurred, however, when boiling milk or water were used. In human Fe absorption studies when the Fe compounds were added to the chocolate drink immediately before consumption, ferrous fumarate was 3.31 % absorbed compared with 2.82% for ferrous sulphate and 2.11 % for ferric pyrophosphate. When the Fe compounds were processed during the manufacture of the chocolate drink powder, the absorption of ferrous fumarate was 5.27 %, ferrous sulphate 2.62 'YO and ferric pyrophosphate 0.55 %. Ascorbic acid had little or no effect on the absorption of ferrous fumarate. It is concluded that food processing can influence the relative absorption of fortification Fe and that, if not reconstituted with boiling milk or water, ferrous fumarate could be a useful compound for the fortification of chocolate drink powders.

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Interaction Of Insecticide Resistance Genes In Field Populations Of Culex Pipiens (Diptera: Culicidae) From Italy In Response To Changing Insecticide Selection Pressure, Bryony C. Bonning, J. Hemingway, R. Romi, G. Majori Mar 1991

Interaction Of Insecticide Resistance Genes In Field Populations Of Culex Pipiens (Diptera: Culicidae) From Italy In Response To Changing Insecticide Selection Pressure, Bryony C. Bonning, J. Hemingway, R. Romi, G. Majori

Bryony C. Bonning

Culex pipiens Linnaeus larvae were collected from various locations in Italy and colonized as separate strains. These were analysed for elevated nonspecific esterase activity and frequency of altered acetylcholinesterase (AChE) mechanisms of insecticide resistance, and bioassayed, to define the cross-resistance spectra conferred by these to organophosphorus and carbamate insecticides. These mechanisms were further characterized by polyacrylamide gel electrophoresis. Elevated esterase A1 (formerly known as Est 3A) which predominated in C. pipiens from Italy in 1985 had been replaced by two esterases, A2 and B2. Altered acetylcholinesterase was still present at high frequencies. Altered and normal acetylcholinesterase were distinguished by differential …

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Gas-Phase Chemistry Of The Dimethylaluminum Oxide Ion And Related Aluminum Oxide Ions: Comparison Of Reactivity With Siloxide Ions, Robert Damrauer, Michèle Krempp, Michael W. Schmidt, Mark S. Gordon Mar 1991

Gas-Phase Chemistry Of The Dimethylaluminum Oxide Ion And Related Aluminum Oxide Ions: Comparison Of Reactivity With Siloxide Ions, Robert Damrauer, Michèle Krempp, Michael W. Schmidt, Mark S. Gordon

Mark S. Gordon

The anion [(CH3hAIOt (1) has been prepared in a flowing afterglow selected ion flow tube (FA-SIFT) by ion selection from the reaction mixture of trimethylaluminum dimer and hydroxide. This unusual ion is quite reactive and has been extensively studied. It reacts with halogen-containing compounds of several types, including fluorobenzene, chlorobenzene, bromofluorobenzene, acetyl chloride, and HF, to give [(CH3hAI(OH)Xt, where X = F, Cl, and Br. Its chemistry with hexafluorobenzene and silicon tetrafluoride has also been detailed as have a number of reactions with carboxylic acids, esters, anhydrides, sulfur-containing neutrals, alcohols, water, and ammonia. The dominant reaction pattern of 1 involves …

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