A study was conducted to find out a suitable vehicle for patch testing in India. Various bases: tested were petrolatum, propylene glycol, polyethylene glycol 400, lanolin, olive, oil and plastobase. The observations suggest that polythylene glycol 400 is the most suitable vehicle for patch testing.
As the sensitivity of the conventional techniques for identifying Shigella spp. and enteroinvasive Escherichia coli (EIEC) causing dysentery cases is low, a PCR assay was evaluated in this study. Analytical sensitivity (2 x 10(2) cfu) of the PCR technique was obtained by artificially spiking negative stool samples with a standard strain of S. flexneri type 2, then determining the detection limit. Specificity (100%) of the method was determined by testing a number of known Shigella and EIEC strains and organisms other than Shigella spp. A total of 300 stool samples collected from children with acute diarrhoea was plated on to two selective agar media after enrichment in Luria broth. Shigella spp. were isolated from 7.7% (23 of 300) and EIEC from 1% (3 of 300) patients. All enriched stool samples were subjected to PCR to amplify the target sequence of invasive plasmid antigen (ipa)H locus, a multicopy element found on the chromosome and invasion plasmid. The stool PCR was positive in 24 of the 26 culture-positive and in 22 culture-negative stools, thus detecting the presence of Shigella spp. or EIEC in 15.3% (46 of 300) of diarrhoea cases. When an ial probe was used for colony hybridistion with enriched stool cultures blotted on to membranes, 9.6% (29 of 300) of dysentery cases were identified as being caused by Shigella spp. or EIEC. Thus the sensitivity of enriched stool culture, colony hybridisation and enriched stool PCR was found to be 54%, 60% and 96%, respectively, when each of the methods was compared to the total microbiologically confirmed cases of dysentery. It was also observed that only 38% (48 of 126) of acute bloody dysentery cases actually had shigella or EIEC infection, as confirmed by laboratory methods. Moreover, this PCR assay could identify a number of untypable Shigella strains (Sh OUT), which would have remained undiagnosed had this assay not been used.
OAK B272 Fission Fragment Folding Angle Distributions for the Systems {sup 11}B+{sup 237}Np, {sup 12}C+{sup 236}U, and {sup 16}O+{sup 232}Th in the Energy Range 1.1
Traffic volumes on local roads have not received much attention from highway planners and researchers, although local roads constitute the majority of road mileage in a state. In recent years the need for reliable estimates of vehicle-miles of travel on local roads has been recognized for the analysis of air quality and highway safety issues. To provide a better understanding of traffic volumes on local roads and to explore alternative methods for estimation, data from Georgia were analyzed by using different statistical procedures. The findings of this analysis are presented, along with the results of an attempt to develop a mathematical model for estimation of local road traffic volumes.
This proceeding is a collection of papers covering new ideas and innovative strategies for solving transportation related air quality problems. The topics include the difficulties, challenges, and improvements in the transportation conformity process; technical improvements to current travel demand models; travel reduction strategies; and applications of transportation control measures. Transportation planners and engineers, urban and regional planners, transportation consultants, and department of transportation affiliates will find the topics informative and useful.
Antibiotic resistance carried on R factors was transferred by conjugation from Escherichia coli B/r and Shigella flexneri 1a to Erwinia spp. Tetracycline resistance (TetR) carried on R factor R100 drd-56 was transferred from E. coli B/r to strains of Erwinia amylovora, E. aroideae, E. atroseptica, E. chrysanthemi, E. cytolytica, E. dissolvens, E. herbicola, E. nigrifluens , and E. nimipressuralis , but not to strains of Erwinia carotovora, E. carnegieana, E. dieffenbachiae, E. oleraceae , and E. quercina . Multiple antibiotic resistance (chloramphenicol, streptomycin, tetracycline; ChlR-StrR-TetR) carried on R factor SR1 was transferred from a clinical isolate of S. flexneri 1a to strains of E. aroideae, E. chrysanthemi, E. herbicola , and E. nigrifluens , but not to strains of other Erwinia spp. The frequency of this transfer was low with receptive cultures of Erwinia spp. and E. coli (F − strain). Antibiotic resistance in the exconjugants showed varying degrees of stability in the presence or absence of acridine orange, depending on the strain tested. The frequencies of segregation to drug susceptibility in the presence of acridine orange, though low, suggest that the elements exist as plasmids in the majority of the Erwinia exconjugants. Multiple antibiotic resistance (ChlR-StrR-TetR) was found to segregate into various resistance classes (ChlR-StrR, StrR-TetR, TetR, StrR, and none) in these exconjugants. The exconjugants of E. amylovora, E. herbicola , and E. nigrifluens , to which R100 drd-56 was transferred from E. coli B/r, were sensitive to the male (F)-specific phage M13. There was a positive correlation between the susceptibility of exconjugants to the F-specific phage M13 and their ability to transfer R100 drd-56 to the recipient cultures of Escherichia coli, Erwinia herbicola, Salmonella typhimurium , and Shigella dysenteriae . Exceptions were, however, noted with Erwinia dissolvens and E. nimipressuralis exconjugants harboring R100 drd-56 ; these exconjugants, although not susceptible to M13, transferred R100 drd-56 to the recipient cultures. The frequency of transfer of R100 drd-56 and the levels of resistance to tetracycline in Erwinia exconjugants were found to differ markedly depending upon the strain employed. Transfer of multiple antibiotic resistance (ChlR-StrR-TetR) from Erwinia exconjugants was not obtained in preliminary trials with an E. coli F − strain as the recipient culture.
The enterobacterium Erwinia carotovora ssp. carotovora strain 71 (hereafter Ecc71) produces extracellular enzymes such as pectate lyase isozymes (Pels), cellulase (Cel), polygalacturonase (Peh) and protease (Prt). These enzymes degrade plant cell wall components and are largely responsible for the elicitation of soft‐rot diseases in plants and plant products. Ecc71 also produces Harpin Ecc , the elicitor of hypersensitive reaction (HR) and the quorum‐sensing signal, N ‐(3‐oxohexanoyl)‐ L ‐homoserine lactone (OHL). OHL controls extracellular enzyme and Harpin Ecc production. The levels of these enzymes, as well as the expression of hrpN Ecc , the structural gene for Harpin Ecc, and ohlI , the gene specifying OHL synthesis, are negatively regulated by RsmA. rsmB , formerly aepH , on the other hand, positively regulates extracellular enzyme production. 6His–RsmA recombinant protein purified from E. coli binds rsmB RNA as indicated by gel mobility shift assays. rsmB comprises 547 bp DNA, which is transcribed from a single start site immediately after a σ 70 ‐like promoter. In Ecc71, two rsmB RNA species are detected: a full‐length 479 base rsmB RNA and a 259 base rsmB ′ RNA. rsmB ′ DNA hybridizes with the 259 base and the 479 base transcripts. A 3′ RNase protection assay revealed that the 259 base and the 479 base RNA species end at the same position immediately after the putative rho‐independent terminator. The expression of rsmB–lacZ transcriptional fusions established that the rsmB ′ RNA is not produced because of the activation of an internal promoter. These data strongly suggest that the 259 base rsmB ′ RNA is derived by processing of the primary rsmB RNA. In Ecc71, rsmB ′ expression driven by the lac promoter causes overproduction of Pel, Peh, Cel and Prt, and accumulation of pel‐1 , peh‐1 , hrpN Ecc and ohlI transcripts. By contrast, a plasmid with the rsmB ′ DNA sequence deleted fails to cause overproduction of the extracellular enzymes in Ecc71. The rsmB ′ effect also occurs in Escherichia coli as glycogen accumulation is stimulated in the presence of rsmB ′. In vivo and in vitro translation as well as mutational analysis of rsmB ′ have established that rsmB ′ RNA does not yield a translational product. Therefore, we concluded that the rsmB ′ RNA itself functions as the regulator. Indeed, the expression of rsmB ′ DNA leads to neutralization of the negative effects of the RNA‐binding protein, RsmA, in Ecc71 and Serratia marcescens strain SM274. We propose a model that explains how RsmA and rsmB control the expression of genes for extracellular enzymes.
This study collected local commercial vehicle data in Knox County, Tennessee, from the U.S. Postal Service (USPS) and two companies engaged in package pickup and delivery (PUD). Another urban commercial vehicle data set with a wider spectrum of freight companies was obtained from North Carolina for comparative analysis. The two data sets were analyzed to develop two sets of values for input parameters for the U.S. Environmental Protection Agency's MOBILE6 model. Statistical tests permitted four aggregated vehicle usage classes to be formed. Two runs of MOBILE6 modeled the two commercial vehicle data sets in their entirety. Four additional runs modeled each vehicle usage class individually through the use of average speed and starts per day specific to the driving pattern of each class. Differences between the values of input parameters and emission factors based on data collected by this study and those based on the default values of MOBILE6 are discussed. Commercial vehicles examined by this study indicated higher annual mileage accumulation rates than the default values. Also their vehicle miles traveled and engine start distributions by hour of day varied considerably from the default values, occurring primarily between the two daily peak traffic periods (morning and evening). The study found higher volatile organic compounds (VOCs), carbon monoxide (CO), and nitrogen oxide emission factors than in default runs for USPS vehicles, whose driving pattern resulted in lower-than-default average speed. Higher VOC and CO emission factors were found for gasoline and diesel package PUD vehicles due to lower-than-default average speeds and higher-than-default starts per day.
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