Incorporation of 15N from ammonium into the N-linked oligosaccharides of an immunoadhesin glycoprotein expressed in Chinese hamster ovary cells

Thirty-six isolates, from man or swine, of Pasteurella multocida subsp. multocida producing (n = 13) or not producing (n = 23) the dermonecrotic toxin (DNT) were studied by numerical analysis, capsular typing and ribotyping. Toxigenic strains were also characterised by restriction fragment length polymorphism (RFLP) of the toxA gene and pulsed-field gel electrophoresis (PFGE). Numerical analysis differentiated the Pasteurella species and subspecies, but did not discriminate between toxigenic and nontoxigenic strains. RFLP demonstrated that toxA was located in a conserved part of the chromosome of all toxigenic strains. Ribotyping provided evidence of a close association between DNT production and one of the six EcoRI ribotypes designated as E2. In contrast, PFGE provided evidence for significant DNA polymorphism amongst the toxigenic strains. Results of phenotypic and genotypic studies suggested that toxigenic strains do not form a clone within the subspecies multocida. No difference was found between toxigenic strains of porcine or human origin by biochemical characterisation, capsular serotyping or genomic typing methods.     

Higher order optical resonant filters based on coupled defect resonators in photonic crystals

In this paper, a general methodology for the design of higher order coupled resonator filters in photonic crystals (PCs) is presented. In the proposed approach, the coupling between resonators is treated as though it occurs through a waveguide with an arbitrary phase shift. The coupling through the waveguide is analyzed theoretically, based on the coupled-mode theory in time. The derived theoretical model suggests a way to extend an equivalent circuit approach, previously demonstrated with a certain value of a phase shift, to the higher order filter design with an arbitrary phase shift. The validity of the proposed approach is confirmed by the design of a third-order Chebyshev filter having a center frequency of 193.55 THz, a flat bandwidth of 50 GHz, and ripples of 0.3 dB in the passband. The characteristics of the designed filter are suitable for wavelength-division-multiplexed (WDM) optical communication systems with a 100-GHz channel spacing. The performance of the designed filter is numerically calculated using the two-dimensional (2-D) finite-difference time-domain (FDTD) method.     

Electrosynthesis and characterization of GaAs in acid solutions by potentiostatic method

Gallium arsenide (GaAs) is one of the important materials used for the fabrication of light emitting diodes, solar cells, microwave devices, etc. In the present work, electrodeposition of GaAs was successfully carried out potentiostatically from an aqueous solution mixture of gallium chloride (GaCl₃) and arsenic oxide (As₂O₃). The optimum deposition potential, pH and bath temperature to synthesize GaAs thin films are found to be −0.8 V versus SCE, 2.0±0.1 and 60 ^°C, respectively. The effects of solution pH, bath temperature and deposition potential on the gallium content of GaAs films are studied. Photoelectrochemical (PEC) solar cells using n-GaAs photo-anode in a polysulphide electrolyte is constructed and I–V, C–V studies are carried out. Various semiconductor parameters such as, flat-band potential, band bending, donor density, depletion layer width are evaluated and the results are discussed.     

Pilot study on the prevalence of Ornithobacterium rhinotracheale infections in food chickens in northwest Germany

Nasosinusal polyposis in the pediatric population is uncommon and its etiology is unclear. In this eleven-year retrospective study, we describe the etiologic features and evaluate the effectiveness of endoscopic sinus surgery in 49 children. Patients were divided into three groups according to whether nasosinusal polyposis was either isolated (n = 14), or associated with either asthma (n = 5) or cystic fibrosis (n = 30). An allergy was present in 10% of patients with isolated polyposis, 80% of patients with polyposis associated with asthma, and 19% of patients with polyposis associated with cystic fibrosis. The indications for surgery were disabling symptoms, specially chronic nasal obstruction, rhinorrhea and mouth breathing, and failure to respond to medical treatment. No surgical complications were encountered. Most patients reported improvement in quality of life with reduction of nasal obstruction in 83% of cases and rhinorrhea in 61%. Minor asymptomatic recurrence (i.e. a few micropolyp localized on the roof of the ethmoid cavity) was observed in 22.7% of the cases in this series, and major recurrence with the same functional symptoms as before surgery in 13.6%. However, recurrences were higher in patients with cystic fibrosis, since minor recurrence with no clinical manifestation was observed in 28.6% of cases and major recurrence in 17.8%. Endoscopic sinus surgery must be decided in collaboration with the pediatric and pulmonary physicians, and must be performed skillfully. With a mean follow-up of 4 years, results in this series are encouraging.     

Investigations into the occurrence and the antibiotic susceptibility of gram negative anaerobes of the genera Bacteroides, Prevotella, Porphyromonas and Fusobacterium in specimens obtained from diseased animals

From different samples of 247 diseased animals (cattle, sheep, goat, horse, pig, dog, cat, rodent, zoo-animals), 410 strains of gram-negative anaerobes were cultured. 297 isolates (72.4%) could be differentiated to the species level by using cultural-biochemical methods, gaschromatography and cell-wall-lipidanalysis. They belonged to 29 different species. For an additional 113 strains (27.6%) only the genus could be determined. Bacteria belonging to the genus Fusobacterium occurred with the highest isolation rates (36% of all strains) in the samples examined, followed by Bacteroides spp. (26.1%), Prevotella spp. (19.9%) and Prophyromonas spp. (17.8%). Fusobacterium necrophorum was the single species isolated most frequently. Antibiotic susceptibility tests by E-test were performed on 100 strains belonging to the the above mentioned genera. Of these strains 18% were resistant to penicillin and 20% to tetracycline. The resistant strains belonged mainly to the Bacteroides fragilis-group. Resistant rates to most other antimicrobial agents tested were Amoxicillin in combination with clavulanic acid: 1%, Chloramphenicol: 3%, Clindamycin:8%. All 100 selected strains proved to be susceptible to Metronidazol.     

A Note on the Parallel Runtime of Self-Stabilizing Graph Linearization

Topological self-stabilization is an important concept to build robust open distributed systems (such as peer-to-peer systems) where nodes can organize themselves into meaningful network topologies. The goal is to devise distributed algorithms where nodes forward, insert, and delete links to neighboring nodes, and that converge quickly to such a desirable topology, independently of the initial network configuration. This article proposes a new model to study the parallel convergence time. Our model sheds light on the achievable parallelism by avoiding bottlenecks of existing models that can yield a distorted picture. As a case study, we consider local graph linearization—i.e., how to build a sorted list of the nodes of a connected graph in a distributed and self-stabilizing manner. In order to study the main structure and properties of our model, we propose two variants of a most simple local linearization algorithm. For each of these variants, we present analyses of the worst-case and best-case parallel time complexities, as well as the performance under a greedy selection of the actions to be executed. It turns out that the analysis is non-trivial despite the simple setting, and to complement our formal insights we report on our experiments which indicate that the runtimes may be better in the average case.     

Detection of acid production from carbohydrates by Riemerella anatipestifer and related organisms using the buffered single substrate test

One hundred and twenty-one Riemerella anatipestifer field strains from wild birds, domesticated poultry and pigs were examined for their ability to produce acid from carbohydrates by using conventional biochemical and buffered single substrate (BSS) test methods. The type strains of the species R. anatipestifer and taxometrically related genera Chryseobacterium and Bergeyella were included in the study. In contrast to 10 indole-positive R. anatipestifer variant strains, only a few of the 111 typical indole-negative R. anatipestifer strains produced acid from dextrin (32%), glucose (17%), maltose (14%) and trehalose (5%) when the conventional test procedure was used. Using the BSS test all the field isolates and the type strain of R. anatipestifer produced acid from one or more carbohydrates, most of them from dextrin (96%), maltose (91%), glucose (87%), mannose (83%), less frequently from fructose (38%) and only in some cases from trehalose (19%). One hundred and six (87%) of the R. anatipestifer strains could be assigned to 8 biovars, based on the diversity of the carbohydrate acidification patterns. The remaining 16 R. anatipestifer isolates gave delayed reactions and displayed 13 different carbohydrate acidification profiles. The Chryseobacterium and Bergeyella type strains also produced acid from more carbohydrates when the BSS test was used. The BSS-carbohydrate acidification pattern of the Chryseobacterium indologenes strain was similar to that of R. anatipestifer biovar 3.