Digital Commons Network^™

Large Plasmids Of Avian Escherichia Coli Isolates, Dawn M. Doetkott, Lisa K. Nolan, Catherine W. Giddings, David L. Berryhill

Lisa K. Nolan

The plasmid DNA of 30 Escherichia coli isolates from chickens was extracted and examined using techniques designed to isolate large plasmids. This plasmid DNA was examined for the presence of certain known virulence-related genes including cvaC, tra7 and some aerobactin-related sequences. Seventeen of the 30 isolates contained from one to four plasmids greater than 50 kb in size. Eleven of these 17 strains possessed plasmids greater than 100 kb in size. Therefore, E. coli isolates of chickens frequently contain large plasmids, and many of these plasmids are likely to contain virulence related sequences.

Quantitative Structure-Activity Relationships For Polychlorinated Hydroxybiphenyl Estrogen Receptor Binding Affinity: An Assessment Of Conformer Flexibility, Steven P. Bradbury, Ovanes G. Mekenyan, Gerald T. Ankley

Steven P. Bradbury

A diverse group of xenobiotics has a high binding affinity to the estrogen receptor (ER), suggesting that it can accommodate large variability in ligand structure. Relationships between xenobiotic structure, binding affinity, and estrogenic response have been suggested to be dependent on the conformational structures of the ligands. To explore the influence of conformational flexibility on ER binding affinity, a quantitative structure—activity relationship (QSAR) study was undertaken with estradiol, diethylstilbestrol, and a set of polychlorinated hydroxybiphenyls (PCHBs) of environmental concern. Although the low-energy minima of the PCHB congeners suggested that interconversions among conformers were likely, the electronic parameters associated with the …

Passage Of Cd18- And Cd18+ Bovine Neutrophils Into Pulmonary Alveoli During Acute Pasteurella Haemolytica Pneumonia, Mark R. Ackermann, M. E. Kehrli Jr., K. A. Brogden

Mark R. Ackermann

CD18 is a subunit for three β2 integrin molecules (Mac-1, p150, 95, LFA-1), which are expressed on the plasma membrane of neutrophils. These molecules mediate passage of neutrophils into sites of infection. In children and animals that lack CD18 expression, neutrophil infiltration is impaired in most tissues. However, in lung, CD18-neutrophils have been identified in the airway spaces during spontaneous episodes of pneumonia. To determine whether CD18 is vital for passage through the pulmonary alveolar wall, lung lobes of cattle with neutrophils that were deficient in CD18 expression (CD18-) and cattle with normal CD18 expression (CD18+) were inoculated with Pasteurella …

Frozen Disorder In A Driven System, Beate Schmittmann, K. E. Bassler

Beate Schmittmann

We investigate the effects of quenched disorder on the universal properties of a randomly driven Ising lattice gas. The Hamiltonian fixed point of the pure system becomes unstable in the presence of a quenched local bias, giving rise to a new fixed point which controls a novel universality class. We determine the associated scaling forms of correlation and response functions, quoting critical exponents to two-loop order in an expansion around the upper critical dimension dc=5.

Capsular Hyaluronic Acid-Mediated Adhesion Of Pasteurella Multocida To Turkey Air Sac Macrophages, Ingrid M. Pruimboom, Richard B. Rimler, Mark R. Ackermann, Kim A. Brogden

Mark R. Ackermann

Serogroup A strains of Pasteurella multocida, the major cause of fowl cholera, are resistant to phagocytosis in nonimmunized birds. Adherence studies with a capsulated strain of P multocida (serotype A:3) and turkey air sac macrophages in culture showed that the bacteria were capable of adhering in large numbers to the macrophages but were not internalized. A noncapsulated variant of the bacteria (serotype -:3) showed little or no adherence and was not internalized. These data indicated that the adhesive properties were caused by the presence of a capsule on the bacteria. The role of capsular hyaluronic acid in adherence to macrophages …

Comparison Of Polyclonal Antibodies To Three Different Preparations Of Mycobacterium Paratuberculosis In Immunohistochemical Diagnosis Of Johne's Disease In Cattle, Judith R. Stabel, Mark R. Ackermann, Jesse P. Goff

Mark R. Ackermann

Polyclonal antisera were raised in rabbits against preparations of live and heat-killed Mycobac-terium paratuberculosis and cell-wall proteins of M. paratuberculosis and were evaluated as diagnostic tools in immunohistochemical staining of bovine tissue. Live preparations of M. paratuberculosis (LMp) were inoculated intraperitoneally or intravenously at 109/ml. Heat-killed M. paratuberculosis (HKMp) was prepared by treatment of bacteria at 85 C for 10 minutes. Cell-wall proteins were isolated from M. paratuberculosis and conjugated to keyhole limpet hemocyanin to improve antigenicity (KLH-CWPMp). The HKMp and KLH-CWPMp preparations were emulsified in incomplete Freund's adjuvant before subcutaneous inoculation of rabbits. Antibody titers in the terminal blood …

The Effect Of Postruminal Amino Acid Flow On Muscle Cell Proliferation And Protein Turnover, James M. Reecy, James E. Williams, Monty S. Kerley, Ruth S. Macdonald, William H. Thornton, Julie L. Davis

Ruth S. MacDonald

An experiment was conducted to characterize the effects of postruminal administration of casein, glutamine, cornstarch, and water on protein turnover and in vitro muscle cell proliferation. Four MARC III steers (205 kg) were fed a protein-restricted bromegrass hay-based diet (2.86 Mcal of DE/kg and 13.6 g of N/kg). Using a 4 x 5 Latin square arrangement balanced for residual effects, casein and glutamine, equal to 50% of basal dietary nitrogen intake, cornstarch, isocaloric with casein infusion, or an equal volume of water was continuously infused into the abomasum of steers. Blood samples, collected every 2 h for 24 h after …

Analysis Of Plasmids Cloned From A Virulent Avian Escherichia Coli And Transformed Into Escherichia Coli Dh5Α, Richard E. Wooley, Penelope S. Gibbs, Harry W. Dickerson, John Brown, Lisa K. Nolan

Lisa K. Nolan

Three of four plasmids from a virulent wild-type avian Escherichia coli were cloned or transformed into an avirulent laboratory recipient E. coli DH5a and tested for the ability to confer a virulence phenotype. The three plasmids transformed into E. coli DH5a were 5, 6, and 56 kb. A fourth plasmid of 64 kb was not successfully transformed. Parameters used to measure virulence included presence of type 1 pili and a smooth lipopolysaccharide (LPS) layer, motility, production of Colicin V, resistance to host complement, and embryo lethality. The 5-kb plasmid encoded for ampicillin resistance, whereas the 6-kb plasmid encoded for tetracycline …

A Stable Β-Silyl Carbocation, Joseph B. Lambert, Yan Zhao

Yan Zhao

The β effect of silicon, whereby a carbon-silicon bond substantially stabilizes an adjacent carbocation (Si-C-C+), has been widely studied mechanistically and exploited synthetically. 1-25 The phenomenon normally is invoked in reactive intermediates. Attempts to prepare stable Me3SiCH2CPh2 + under standard magic acid conditions led to loss of trimethylsilyl and observation only of CH3CPh2 +.11 A 2-(trimethylsilyl)allyl cation stable only at -100 °C did not comprise a β-effect system, as the silyl group destabilized the ion and the C-Si bond was orthogonal to the carbocation ð orbitals.21 Siehl and Kaufmann23 prepared 1-arylvinyl cations stabilized by β-silyl groups in magic acid at …

Phase Transitions In Driven Bilayer Systems: A Monte Carlo Study, C. C. Hill, R. K. P. Zia, Beate Schmittmann

Beate Schmittmann

We investigate the phase diagram of a system with two layers of an Ising lattice gas at half filling. In addition to the usual intralayer nearest neighbor attractive interaction, there is an interlayer potential J. Under equilibrium conditions, the phase diagram is symmetric under J→−J, though the ground states are different. The effects of imposing a uniform external drive, studied by simulation techniques, are dramatic. The mechanisms responsible for such behavior are discussed.

Multicentric Malignant Lymphoma In A Pallid Bat, Claire B. Andreasen, Julie R. Dulmstra

Claire B. Andreasen

A 2.5-year-old, female pallid bat (Antrozous pallidus) was captured in Oregon (USA) in 1990 and later died in 1992. At the time of death, abdominal distension due to ascites, splenomegaly, and hepatomegaly, and a cheek mass were noted. Based on histologic examination of these tissues, a diagnosis of multicentric lymphoma was made. Retroviral particles were not found on electron microscopic examination.

Построение Редуцированного Физического Гамильтониана Для Сферически-Симметричной Гравитации, Николай Заркевич

Nikolai A. Zarkevich

No abstract provided.

Porcine Reproductive And Respiratory Syndrome Virus Enters Cells Through A Low Ph-Dependent Endocytic Pathway, Luiz C. Kreutz, Mark R. Ackermann

Mark R. Ackermann

The entry pathway of porcine reproductive and respiratory syndrome virus (PRRSV) into MARC-145 cells was investigated using a variety of drugs that interfere with the pH of intracellular vesicles by different mechanisms. Virus entry was assessed by measuring viral RNA replication or production of infectious virus. Chloroquine, ammonium chloride and bafilomycin A1 inhibited RNA replication or production of infectious virus in a dose-dependent manner. These drugs inhibited virus replication when added to the cells prior to, at infection or soon after infection. Moreover, the effect of chloroquine on PRRSV replication was reversible under acidic conditions of the media. Taken together, …

Alimentary And Respiratory Tract Lesions In Eight Medically Fragile Holstein Cattle With Bovine Leukocyte Adhesion Deficiency (Blad), Mark R. Ackermann, M. E. Kehrli Jr., J. A. Laufer, L. T. Nutsz

Mark R. Ackermann

Lesions in the alimentary tract were studied in eight medically fragile Holstein cattle homozygous for the bovine leukocyte adhesion deficiency (BLAD) allele as determined by polymerase chain reaction and restriction endonuclease analysis. These cattle received institutional medical care but died or were euthanatized because of chronic debilitation associated with diarrhea (6/8) and pneumonia (4/8). The six cattle with diarrhea had acute (n = 3) or chronic (n = 3) intestinal ulcers, but the other two remained relatively healthy for 3 years and did not develop intestinal tract ulcers. Ulcerated areas were present in the small intestine in six animals, and …

Electronic Origins Of Ordering In Multicomponent Metallic Alloys: Application To The Cu-Ni-Zn System, J. D. Althoff, Duane D. Johnson, F. J. Pinski, J. B. Staunton

Duane D. Johnson

We investigate the ordering tendencies of the fcc Cu-Ni-Zn system using a recently developed first-principles, density-functional-based theory of atomic short-range order (ASRO) in disordered substitutional alloys of an arbitrary number of components. We find for the binary alloys a variety of effects which should lead to competition in the ternaries: commensurate ordering (Ni-Zn), long-period ordering (Cu-rich Cu-Zn), and clustering (Cu-Ni), in agreement with experiment. We calculate the ASRO of various disordered ternary alloys (as described by the Warren-Cowley pair-correlation function) and discuss its relationship to the electronic structure of the binary and ternary disordered alloys. We find [100]-type ASRO over …

Β Effect Of Phosphorus Functionalities, Joseph B. Lambert, Yan Zhao

Yan Zhao

Diphenylphosphinoyl (−P(O)Ph2) and diphenylthiophosphinoyl (−P(S)Ph2) respectively are modest and strong β-effect functionalities. When these groups are antiperiplanar to mesylate, the substrates solvolyze through unimolecular ionization. In contrast, substrates with the synclinal (gauche) arrangement react bimolecularly with solvent. The anti/gauche rate ratio is 440 for the oxide and 3.2 × 106 for the sulfide at 25 °C. The antiperiplanar sulfide in fact reacts 220 times more rapidly than the analogous cyclohexyl substrate at 25 °C, despite the strong electron-withdrawing nature of diphenylthiophosphinoyl. The α-secondary hydrogen/deuterium kinetic isotope effects of 1.21 for the anti oxide and 1.26 for the anti sulfide suggest …

Low Calcium Diet And 1,25-Dihydroxyvitamin D3 Infusion Modulate Immune Responses During Mycobacterium Paratuberculosis Infection In Geige Mice, Judith R. Stabel, Jesse P. Goff, Diana L. Whipple, Mark R. Ackermann, Timothy A. Reinhardt

Mark R. Ackermann

A 12-month study was conducted to evaluate the effects of feeding a low calcium (Ca) diet or 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) infusion on the persistence of Mycobacterium paratuberculosis infection using a mouse model. Male beige mice 6–8 weeks of age were assigned to one of the following treatments: (1) non-infected, (2) infected, (3) non-infected/1,25(OH)2D3, (4) infected/1,25(OH)2D3, and (5) infected/low Ca (0.15%) diet. Infected mice were inoculated intravenously with live M. paratuberculosis. At 1, 6 and 12 months postinfection, mice in Treatments 3 and 4 were implanted subcutaneously with mini-osmotic pumps to deliver 1,25(OH)2D3. Infusion with 1,25(OH)2D3 exacerbated M. paratuberculosis infection in …

Comparison Of Sensors And Techniques For Crop Yield Mapping, Stuart J. Birrell, Kenneth A. Sudduth, Steven C. Borgett

Stuart J. Birrell

The implementation of site-specific crop management is dependent on the variations in yield and yield potential within a field. Crop yield maps are important for both the implementation and evaluation of site-specific crop management strategies. Management decisions and evaluations based on yield maps must take into consideration the accuracy and resolution of the maps.

An impact-based yield monitor and a volumetric yield monitor were compared. The effect of different dynamic models of combine grain flow on the calculated instantaneous yields were investigated. Both simple time delay models and first order models could be used to model the grain flow. In …

Variation In Cell Dimensions And Fibril Angle For Two Fertilized Even-Aged Loblolly Pine Plantations, Douglas D. Stokke, Todd F. Shupe, Elvin T. Choong, Mark D. Gibson

Douglas D. Stokke

Increment core samples were obtained from randomly selected, nine-year-old lohlolly pine (Pinus faeda L.) in two even-aged plantations in Louisiana in order to determine the variation in cell dimensions and fibril angle of the sites. The Homer site is representative of the growing conditions in north Louisiana, and the Bogalusa site is typical of the conditions in southeastern Louisiana. Both sites were subjected to similar site preparation and weed control and were fertilized in the juvenile period. The anatomical properties that were measured include: fiber length, cell-wall thickness, and microfibril angle (MFA). Observations were made in order to compare corewood …

Estimating One-Electron Reduction Potentials Of Quinones, Steven P. Bradbury, Ovanes G. Mekenyan, V. B. Kamenska

Steven P. Bradbury

The one-electron reduction potential ∗ E1 7 of benzo-, naphtho-and anthracenequinones is related to their ability to undergo redox cycling and elicit cytotoxicity through oxidative stress. To evaluate a general approach to estimate the E1 7 of benzo-, naphtho-and anthracenequinones, QSAR approaches based on gas phase and solvation based methods were employed. Stereoelectronic descriptors of ground state quinones, respective intermediates of the redox cycle, and the di erences in parameters for the transition between intermediates were evaluated. The variation of E1 7 was correlated with descriptors of the parent quinones and speci c transition parameters. The energy of the highest …

Presettlement Vegetation Of The Lower Chippewa River Valley, Lisa A. Schulte-Moore, William J. Barnes

Lisa A. Schulte Moore

The lower Chippewa River of west-central Wisconsin is the portion that flows southwest from the city of Eau Claire to the Mississippi River at Nelson. The river has a gentle gradient of about 0.8 m/km and highly erodible banks of sand and gravel. The river valley occurs between 35 m to 70 m below the surrounding upland, is between 1 and 5 km wide, and was formed primarily by glacial meltwaters. The floodplain is defined by annual high water levels and is generally below the 25 year flood recurrence interval, which on this part of the Chippewa River is >5m …

2,3, 7,8-Tetrachlorodibenzo-P-Dioxin, Steven P. Bradbury

Steven P. Bradbury

Since 1985, the United States Environmental Protection Agency (USEPA) has classified 2,3,7,8-tetrachloro-p-dioxin (TCDD) as a probable human carcinogen; subsequently, sources of TCDD in the environment have been regulated on the basis of animal cancer rates extrapolated to doses associated with human exposures. Two major activities have prompted the decision to reassess this approach for evaluating TCDD toxicity and its associated risks. First, an epidemiological study of cancer mortality in U.S. chemical workers by the National Institute of Occupational Safety and Health provided evidence of TCDD-mediated human carcinogenicity (Fingerhut et al. 1991 ). Second, at a 1990 Banbury conference a consensus …

On The Importance Of Chain Reptation In Models Of Dissolution Of Glassy Polymers, Balaji Narasimhan, Nikolaos A. Peppas

Balaji Narasimhan

Polymer dissolution was described by chain reptation incorporated into penetrant transport. The penetrant concentration field was divided into three regimes which delineate three different transport processes. Solvent penetration through the polymer was modeled to occur as a consequence of a diffusional flux and an osmotic pressure contribution. Species momentum balances were written that coupled the polymer viscoelastic behavior with the transport mechanism. Transport in the second penetrant concentration regime was modeled to occur in a diffusion boundary layer adjacent to the rubbery-solvent interface, where a Smoluchowski type diffusion equation was obtained. The disentanglement rate of the polymer is given by …

An Efficient Fast‐Multipole Algorithm Based On An Expansion In The Solid Harmonics, H.Y. Wang, Richard Alan Lesar

Richard Alan Lesar

We present an efficient variant of the fast‐multipole method for calculating long‐range interactions in three‐dimensional Coulombic systems. Using a multipole expansion based on the solid harmonics instead of the more common spherical harmonics leads to a greater increase in computational efficiency than a recently‐reported fast‐Fourier transform method, with none of the overhead associated with that approach.

Serum Chemistry Of Bowhead Whales (Balaena Mysticetus), Jerry R. Heidel, L. Michael Philo, Thomas F. Albert, Claire B. Andreasen, Bernadette V. Stang

Claire B. Andreasen

Sera of 19 male and female bowhead whales (Balaena mysticetus) collected near Barrow, Alaska (USA) between 30 August and 13 October 1992 were evaluated for 18 serum chemistry values. Male bowhead whales had significantly greater creatinine and sodium concentrations, and significantly lower glucose concentrations than females. Pregnant females had greater triglyceride levels than non-pregnant females. The mean concentrations of creatinine, blood urea nitrogen, alkaline phosphatase, total bilirubin, total protein, sodium, potassium, chloride, phosphorus, and calcium were similar to those previously reported from bowhead whales. High aspartate aminotransferase and creatine kinase levels were attributed to muscle damage associated with harpooning.

Comparison Of The Effect Of Different Opsonins On The Phagocytosis Of Fluorescein-Labeled Staphylococcal Bacteria By Chicken Heterophils, Claire B. Andreasen, James R. Andreasen Jr., Anita E. Sonn, Julie A. Oughton

Claire B. Andreasen

Heterophil phagocytosis of fluorescein-labeled staphylococcal bacteria was analyzed by flow cytometry. Opsonization with two types of normal pooled sera and staphylococcal antisera significantly increased bacterial phagocytosis compared to samples without an opsonin. The staphylococcal antisera did not significantly increase bacterial phagocytosis compared to the normal pooled sera. Opsonization appears to increase bacterial phagocytosis but specific antisera may not increase phagocytosis beyond that caused by pooled normal sera.

Development Of An Enzyme-Linked Immunosorbent Assay (Elisa) For Quantification Of Skeletal Muscle Calpastatin, M. E. Doumit, Steven M. Lonergan, J. R. Arbona, J. Killefer, M. Koohmaraie

Steven M. Lonergan

An indirect antibody ELISA was developed for rapid and sensitive quantification of skeletal muscle calpastatin. Polyclonal antibodies were raised in rabbits against recombinant calpastatin, corresponding to domains 2, 3, and 4 of bovine skeletal muscle calpastatin. Western blot analysis revealed that these antibodies specifically recognize an immunoreactive calpastatin protein of approximately 130 kDa in prerigor skeletal muscle extracts. The intensity of the immunoreactive bands corresponds qualitatively with assayable calpastatin activity. For ELISA development, optimum dilutions of sample, primary anti-calpastatin antibody, and peroxidase-conjugated secondary antibody were determined by titration. A dilution optimum for coating of Immulonâ 4 (Dynatech) plates was observed …

Low‐Frequency Perturbation Theory In Eddy‐Current Non‐Destructive Evaluation, Nicola Harfield, Y. Yoshida, John R. Bowler

Nicola Bowler

A method is presented by which series solutions for the impedance change in an eddy‐current test probe due to closed cracks in a non‐magnetic, conducting half‐space can be derived at low frequency. The series solution is applicable for flaws whose dimensions are much smaller than the electromagnetic skin‐depth. The problem is formulated using an approach in which the flaw is represented by an equivalent distribution of current dipoles. The electric field scattered by the flaw is then written as an integral, over the flaw, of the product of the dipole density distribution and an appropriate Green’s function. Terms in the …

Synthesis And Characterization Of A New Class Of Μ3-Oh-Bridged Trimers That Contain Octahedrally Coordinated Divalent Metal Ions Bridged By Three Acetate Ligands And A Unique Catecholate Ligand. Solid State Molecular Structures Of The [(Py)5mii3(Oac)3(Μ3-Oh)((Cat)] Complexes (M = Mn(Ii), Fe(Ii), Co(Ii), Ni(Ii)), R.A. Reynolds, Edward Yu, W.R. Dunham, D. Coucouvanis

Edward Yu

The synthesis and structural characterization of a new class of “basic” trinuclear acetate clusters with solely divalent metal ions and a central μ3-OH ligand are reported. These molecules with the [(py)5MII3(OAc)3(μ3-OH)(cat)] stoichiometry (M = Mn, Fe, Co, Ni) are X-ray isomorphous and isostructural and contain octahedrally coordinated metal ions. The core consists of an antiferromagnetically coupled M3 unit with the metals arranged in the corners of an isosceles triangle. Two of the M−M distances vary between 2.98 and 3.16 Å, and the longer M−M distance is observed between 3.65 and 3.76 Å. As expected from the relative ionic radius lengths, …

Evaluation Of Gps For Applications In Precision Agriculture, Steven C. Borgelt, John D. Harrison, Kenneth A. Sudduth, Stuart J. Birrell

Stuart J. Birrell

Location coordinate information is needed in precision agriculture to map in-field variability, and to serve as a control input for variable rate application. Differential global positioning system (DGPS) measurement techniques were compared with other independent data sources for sample point location and combine yield mapping operations. Sample point location could be determined to within 1 m (3 ft) 2dRMS using C/A code processing techniques and data from a high-performance GPS receiver. Higher accuracies could be obtained with carrier phase kinematic positioning methods, but this required more time and was a less robust technique with a greater potential for data acquisition …