The occurrence of ambient temperature-regulated adhesins, curli, and the temperature-sensitive hemagglutinin tsh among avian Escherichia coli

Escherichia coli establishes a secondary respiratory tract infection in birds following inhalation of contaminated dust and litter particles. Escherichia coli express adhesins under conditions reflective of the ambient temperatures present in poultry houses. These microbial adhesins allow E. coli to attach to cell types that it initially encounters in the respiratory tract. Ambient temperature-regulated adhesins represent a new class of bacterial hemagglutinins that include pili and the thin, aggregative, flexible filaments known as "curli." This study examines the occurrence of the ambient temperature-regulated adhesins, curli (crl, csgA), and an avian-specific, temperature-sensitive hemagglutinin, tsh, among avian and mammalian E. coli isolates. The avian hemagglutinin gene tsh was present in approximately 46% of clinical avian E. coli isolates. This gene was not detected among commensal E. coli isolated from healthy broiler chickens. Unlike tsh, curli genes were ubiquitous among E. coli. However, curli were observed in only half of the avian E. coli examined by electron microscopy. Curli were not present among several nonavian E. coli positive for crl and csgA. Approximately 25% of avian E. coli isolates agglutinated chicken erythrocytes when bacteria were grown at room temperature. Hemagglutination was not specific to E. coli isolated from poultry. Presence of either tsh or curli genes was not indicative of an isolate's ability to agglutinate chicken red blood cells. No discernible structures were observed mediating attachment of the bacteria to chicken red blood cells. An additional avian-specific hemagglutinin appears to be present among avian E. coli.     

Current induced resistive state in cylindrical superconducting films. I. Critical currents measurements

We present measurements of critical currents and critical magnetic fields in cylindrical indium films. The most interesting result is that the ratio of the experimental critical current I_c1 to Silsbee's critical value I_c0 practically does not depend on temperature. This ratio was strongly dependent on the film thickness changing from I_c1 0.18I_co for the film thickness d = 0.3m to I_c1 1.3I_co for d = 5.5m. These results cannot be explained in the framework of the existing theoretical models.On leave from Kapitza Institute for Physical Problems, 117334 Moscow, Russia.     

Application of Cs salt of 12-tungstophosphoric acid supported on SBA-15 mesoporous silica in NO x storage

Cs salt of 12-tungstophosphoric acid (HPW) was deposited simultaneously at the external surface of the SBA-15 silica microcrystals and inside its mesoporous channels at loading of 60 wt% and Cs/W ratio in the range between 0.9 and 2, followed by impregnation of 1 wt% Pt. The performance of the Pt/CsHPW/SBA-15 composite materials was tested in the NO _x storage. The optimal NO _x storage capacity and efficiency were achieved at Cs/W of 1.5. The dispersion of CsHPW on SBA-15 led to a significant decrease of its crystal size (5–13 nm) compared with bulk HPW and HPW supported on titania (28–29 nm). Pt/CsHPW/SBA-15 displayed lower NO _x absorption capacity but much higher absorption and desorption efficiency than the reference Pt/HPW and Pt/HPW/TiO₂ materials. Consequently, Pt/CsHPW/SBA-15 displayed a better performance in short lean (2 min)—rich (1 min) absorption-desorption cycles. The novel Pt/CsHPW/SBA-15 nanocomposites presents the basis for improved storage material for NO _x removal from lean exhaust gases in highly dynamic aftertreatment technologies.     

Modeling of the Current Distribution in Aluminum Anodization

The growth of porous anodic Al₂O₃ films, formed potentiostatically in continuously stirred 15 wt.% H₂SO₄ electrolyte was studied as a function of the anodization voltage (14–18 V), bath temperature (15–25 °C) and anodization time (15–35 min). The variation of the anodic surface overpotential with the current density was measured experimentally. The film thickness at the more accessible portions of the anode was observed to increase with the anodization voltage and the bath temperature. However, the film thickness on the less accessible portions of the anode did not significantly change with the voltage or the bath temperature. This indicates that the anodization process at the more accessible regions is more strongly influenced by the surface processes than by the electric migration within the electrolyte. Furthermore, analysis confirms that the major portion of the film resistivity resides within a thin sub-layer that does not vary with the anodization time, and the growing anodic layer contributes only marginally to the overall film resistance. Computer aided design software was employed to simulate the current density distribution. For the range of process parameters studied, the electrochemical CAD software predicts accurately the measured thickness distribution along the anode.     

Deep desulfurization of diesel fuels: kinetic modeling of model compounds in trickle-bed

Five catalysts with different hydrodesulfurization (HDS) and hydrogenation activity were tested in HDS of fresh crude heavy atmospheric gas oil (HAGO) (1.33 wt% S), two partially hydrotreated HAGO (1100 and 115 ppm S) and two model compounds, dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT), dissolved in model solvents and HAGO. Aromatic compounds in the liquid decreased significantly the HDS rate of 4,6-DMDBT, especially for catalysts with high hydrogenation activity. H₂S displayed a similar inhibition effect with all catalysts. These effects were extremely pronounced in HAGO where the DBT HDS rate decreased by a factor of 10 while 4,6-DMDBT – of 20 relative to paraffinic solvent. The feasibility of using a highly active hydrogenation catalyst for deep HDS of HAGO is diminished by the strong impact of aromatics.     

A novel source of wheat fiber and protein: effects on fecal bulk and serum lipids

BACKGROUND: Polyethylene glycol (PEG) 3350 is a non-absorbable, non-metabolised osmotic agent used in lavage solutions for gut cleansing. AIMS: To compare the efficacy of PEG and lactulose in chronic constipation. METHODS: A total of 115 patients with chronic constipation entered a multicentre, randomised, comparative trial. They initially received two sachets containing either PEG (13 g/sachet) or lactulose (10 g/sachet) and were given an option to change the dose to one or three sachets/day, depending on response. RESULTS: Ninety nine patients completed the trial. After four weeks, patients in the PEG group (n=50) had a higher number of stools and a lower median daily score for straining at stool than patients in the lactulose group (n=49). Overall improvement was greater in the PEG group. Clinical tolerance was similar in the two groups, but flatus was less frequently reported in the PEG group. The mean number of liquid stools was higher in the PEG group but the difference was significant only for the first two weeks. There were no serious adverse events and no significant change in laboratory tests in either group. At the end of the study, the number of sachets used by the patients was 1.6 (0.7)/day in the PEG group and 2.1 (0.7)/day in the lactulose group. Sixty one patients completed a further two months open study of one to three sachets PEG daily; there was no loss of efficacy and no serious toxicity. Conclusion: Low dose PEG 3350 was more effective than lactulose and better tolerated.     

No Major Role for Binding by Salivary Proteins as a Defense Against Dietary Tannins in Mediterranean Goats

We investigated whether Mediterranean goats use salivary tannin-binding proteins to cope with tannin-rich forages by determining the affinity of salivary or parotid gland proteins for tannic acid or quebracho tannin. Mixed saliva, sampled from the oral cavity, or parotid gland contents were compared to the intermediate affinity protein bovine serum albumin with a competitive binding assay. Goats that consume tannin-rich browse (Damascus) and goats that tend to avoid tannins (Mamber) were sequentially fed high (Pistacia lentiscus L.), low (vetch hay), or zero (wheat hay) tannin forages. Affinity of salivary proteins for tannins did not differ between goat breeds and did not respond to presence or absence of tannins in the diet. Proteins in mixed saliva had slightly higher affinity for tannins than those in parotid saliva, but neither source contained proteins with higher affinity for tannins than bovine serum albumin. Similarly, 3 months of browsing in a tannin-rich environment had little effect on the affinity of salivary proteins for tannin in adult goats of either breed. We sampled mixed saliva from young kids before they consumed forage and after 3 months of foraging in a tannin-rich environment. Before foraging, the saliva of Mamber kids had higher affinity for tannic acid (but not quebracho tannin) than the saliva of Damascus kids, but there was no difference after 3 months of exposure to tannin-rich browse, and the affinity of the proteins was always similar to the affinity of bovine serum albumin. Our results suggest there is not a major role for salivary tannin-binding proteins in goats. Different tendencies of goat breeds to consume tannin-rich browse does not appear be related to differences in salivary tannin-binding proteins.     

Dual electrical properties of quench-condensed mercury films. Dependence on the substrate material

It is shown that the conductivity onset in cold deposited Hg films on glass substrates covered with a SiO layer corresponds to te film thickness of 4–5 Å in a contrast to films deposited on pure glass, where the conductivity onset can be observed only at 10–15 times higher thicknesses. Study of superconducting properties of films is also presented. We believe that chemical bonds between metallic atoms themselves and their chemical interaction with atoms of the substrate are very important for formation of the film structure and responsible for a completely different behavior of films deposited onto different substrates.     

Transvasal closure of interatrial defects using the Babic double-umbrella occluder system

The purpose of the study was to assess the feasibility and safety of closure of atrial septal defects and patent foramen ovale by means of a new interventional technique. Transvasal closure of ostium secundum atrial septal defect and patent foramen ovale was performed in 18 patients using an occluder system for atrial septal defects. Two patients had undergone unsuccessful direct surgical closure years before. Implantation and follow-up were controlled using radiographic views both with and without contrast injection, transthoracic and multiplane transesophageal echocardiographic imaging, color Doppler sonography, and computed tomography. The defect was closed in 16 patients using 19 procedures. Removal of the devices through the sheath was indicated in 4 patients because of placement failure. Intraprocedural complications were ventricular fibrillation in one patient and fixation of the device in Chiari's network in an additional one. During 7-26 months follow-up occluder damage was seen in two patients and perforation of the left atrium in one patient. Thickening on the occluder surface was observed in two patients. There was no death. The system for closure of atrial septal defect is feasible and safe in patients with defects < or = 27 mm in diameter. Long-term observation of outcome is limited yet.     

Item availability in cryptomnesia: Assessing its role in two paradigms of unconscious plagiarism.

Three experiments explored the assumptions underlying the relative strength model used by R. L. Marsh and G. H. Bower (see record 1993-32215-001) to account for laboratory-induced cryptomnesia (unconscious plagiarism). That model accounted for source and occurrence forgetting in unconscious plagiarism paradigms by assuming that items from different sources possess different strengths. That assumption had never been explicitly tested. In Experiment 1, results from a lexical-decision task supported the strength model using a word-search puzzle paradigm. In Experiment 2, which used a category generation paradigm, similar results demonstrated that later plagiarized items were indeed more available compared with items that were not later plagiarized. In Experiment 3, the strength of self- versus other-generated items was independently manipulated, resulting in large amounts of cryptomnesia that differed in ways specifically predicted by the model. These results are discussed in light of current models of source attributions and memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)