Pulsed field gel electrophoresis of related Escherichia coli O157 isolates associated with beef cattle and comparison with unrelated isolates from animals, meats and humans

The pulsed field gel electrophoresis (PFGE) diversity of 51 related Escherichia coli O157 isolates, associated with beef cattle from a single-farm-to-single abattoir (SF-SA) chain of events was determined. The 51 related E. coli O157 isolates from hides, faeces or carcasses of SF-SA cattle produced 11 different PFGE profiles. Also, the PFGE diversity of 6 isolates, associated with a second cattle abattoir, was determined; only two PFGE profiles were found. On the other hand, the PFGE diversity of 136 unrelated E. coli O157 isolates (from healthy meat animals, retail meats and cases of human disease) was also determined. The 136 unrelated E. coli O157 isolates produced 78 different PFGE profiles, most of which (approximately 70%) comprised only one isolate. Overall, the results showed: (a) related E. coli O157 isolates (from both SF-SA events, and the second abattoir) had a markedly narrower clonal profile than the 136 unrelated E. coli O157 isolates; (b) the isolation of identical PFGE types from hide, lairage environment, and carcasses confirms the significance of cross-contamination (both pre-slaughter and during skinning) taking place at abattoirs; and (c) PFGE typing of isolates offers a good tool for tracking sources/routes of such cross-contamination. Such cross-contamination may lead to originally E. coli O157-free animals (and resultant carcasses) becoming contaminated during farm-slaughter-dressing chain of events, so development of efficient control strategies is required.     

The interactive effects of listwide control, item-based control, and working memory capacity on Stroop performance.

Hypothesized top-down and bottom-up mechanisms of control within conflict-rich environments were examined by presenting participants with a Stroop task in which specific words were usually presented in either congruent or incongruent colors. Incongruent colors were either frequently (high contingency) or infrequently (low contingency) paired with the word. These items were embedded within lists consisting of either 100% congruent or 100% incongruent filler items to create mostly congruent or mostly incongruent lists. Results indicated a significant item-specific congruency effect, which was largest for high contingency responses and within mostly congruent lists. In addition, a significant listwide congruency effect was obtained, and this interacted with working memory capacity (WMC). There were larger listwide congruency effects for low WMC individuals. Finally, the pattern of Stroop interference across lists for low WMC individuals was dependent upon the congruency of the preceding trial. These results support multiple forms of cognitive control, as well as contingency learning, as mechanisms underlying proportion congruence effects in Stroop and other conflict tasks. These findings are interpreted within Braver, Gray, and Burgess's (2007) dual mechanisms of control theory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

What makes group MET work? A randomized controlled trial of college student drinkers in mandated alcohol diversion.

Nationally, college drinkers exhibit the highest rates of alcohol consumption and represent the largest percentage of problem drinkers. Group motivational enhancement therapy (GMET) has been found to catalyze problem drinking reductions among college student samples. Although research supporting the use of single-session GMET in college samples (general and mandated) is emergent, no studies have evaluated a comprehensive model of the potential active ingredients of this group intervention. College students (N = 206; 88% White; 63% men; M age = 18.6) mandated to a university alcohol diversion program were randomly assigned to 1 of 3 conditions: the standard-of-care 2-session “Focus on Alcohol Concerns” education group (FAC), a single GMET, or a single alcohol information-only control group (AI) to evaluate the role of 5 putative mediators: readiness to change, self-efficacy, perceived risk, norm estimates, and positive drinking expectancies. At 3- and 6-month follow-ups, GMET students demonstrated greater reductions in problem drinking outcomes (drinks per drinking day, hazardous drinking symptoms, and alcohol-related problems). Of the 5 mediators proposed, only self-efficacy emerged as a significant mediator. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

With great expectations, can two "wrongs" prime a "right"?

The proportion of related prime-target pairs (relatedness proportion, RP) and prime-target stimulus onset asynchrony (SOA) was varied to determine the involvement of strategic priming mechanisms in the reduction in semantic priming that occurs when a target follows an unmasked prime that itself receives immediate repetition priming from a masked prime. At 300-ms and 1,200-ms SOAs, (a) strategic semantic priming was operating, in that priming from a nonrepeated prime increased as RP increased from .25 to .75, and (b) for both RPs, prime repetition reduced semantic priming. At a 167-ms SOA, (a) priming from a nonrepeated prime was unaffected by RP, suggesting that strategic priming was not operating, and (b) for both RPs, prime repetition did not reduce semantic priming. Because prime repetition did not reduce priming at the 167-ms SOA (when only spreading activation should have been mediating semantic priming), the reduction in semantic priming produced by prime repetition is not evidence against spreading activation automaticity. Possible mechanisms through which prime repetition reduces semantic priming are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of nicotine deprivation on alcohol-related information processing and drinking behavior.

This study examined the influence of smoking cues and nicotine deprivation on responses to alcohol among hazardous drinkers. Fifty-six daily smoking, hazardous drinkers were exposed to either smoking cues or control cues after either 6 hr of nicotine deprivation or no deprivation. Urges to drink alcohol, alcohol-related cognitive processing, and alcohol consumption were assessed after cue exposure. Results indicated that nicotine deprivation increased urges to drink, the accessibility of alcohol outcome expectancies, and the volume of alcohol consumed. There was little influence of the smoking cue manipulation on these processes. Implications for understanding the mechanisms underlying alcohol–tobacco interactions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retrieval of cloud base heights from passive microwave and cloudtop temperature data

Water vapor profiling algorithms that treat liquid clouds explicitly yield a cloud base height as a byproduct. A single case of a water vapor profile retrieval using a combination of the SSM/T-2 on the DMSP satellite and cloud parameters from the AVHRR on the NOAA satellite retrieved a reasonable cloud base. While hardly definitive, this case is suggestive. The authors examine the cloud base signal in a combination of the SSM/1 and SSM/T-2 on the DMSP satellite from a theoretical point of view. It is shown that the signal is strong enough for a useful retrieval only over the ocean. For low altitudes, a cloud top temperature (CTT) constraint, as could be provided from an infrared radiometer, is required. While difficult with the DMSP-NOAA satellite combination, this has become much easier with the recent launch of NOAA-K with the AMSU-B and AVHRR. It is shown that the signal is acceptable over the relevant range of cloud liquid water content values. To achieve useful results, some local tuning of the algorithm will be necessary. This tuning could take the form of water vapor profile covariance matrices, climatological estimates of the cloud liquid water density, or purely empirical methods. Broken and multilayer clouds provide additional complications to the problem     

Database/domain approach to distributed systems management

Distributed systems are now used in a variety of environments and at different levels within business organizations, both in offices and factories. As the number of devices attached to these systems grows, and as the systems become internetworked together, management tools become increasingly essential to retain control of the complete distributed system. A distributed systems management model is presented which is suitable for implementation in the real world. A key feature of this model is its construction from independently managed domains. The DSM functionality is distributed in operation, and overall control is achieved through the cooperation of individual domain management systems, in which human managers make use of management tools provided to control their own domain of responsibility. Another feature of the design is the use of management databases, one per domain. A commercially available database has been used to demonstrate the feasibility of the design. DSM processes are used to query and update the MDBs, and human managers having the appropriate authority may also directly access the MDBs. Monitored management information on all managed objects within a domain is processed and stored in that domain's MDB. The idea for the MDB is derived from the concept of a management information base described in the International Organization for Standardization Open Systems Interconnection management standards. However, whereas the OSI MIB is a virtual concept, the MDB is a physical realization, and it is not intended to be a direct implementation of the MIB as such.     

A side chain at position 48 of the human immunodeficiency virus type-1 protease flap provides an additional specificity determinant

Substitution of glycine with glutamic acid at position 48 of the human immunodeficiency virus protease resulted in an enzyme with reduced activity on one of the protease processing sites in the viral Pol polyprotein precursor. Cleavage at this site was restored by a second-site substitution in the substrate replacing an aspartic acid with either glycine or asparagine. These results suggest that the glutamic acid side chain in the mutant protease has an unfavorable charge-charge interaction with this position in the substrate. Cleavage of a processing site in the viral Gag polyprotein precursor with the mutant enzyme was enhanced, and this enhancement was dependent on the presence of an arginine residue in the substrate, again suggesting a charge-charge interaction. The potential for such interactions was confirmed using molecular modeling. The effect of the position 48 substitution was attributed to a 10-fold increase in Km for the processing site in Pol. These results indicate that the addition of a side chain at position 48 can alter the specificity of the HIV-1 protease to substrate in a sequence specific manner and that compensatory changes can be made in the substrate.