Cleaning and handling implements as potential reservoirs for bacterial contamination of some ready-to-eat foods in retail delicatessen environments

This study assessed the association of bacteria with cleaning tools, such as floor mops (n = 25) and cleaning cloths (n = 39), and handling devices, such as disposable plastic gloves (n = 20), used during filled baguette and assorted salad preparation in four selected retail delicatessens in Johannesburg, South Africa. Samples of each cleaning or handling tool were prepared for aerobic (APC), coliform (CC), Escherichia coli (EC), Bacillus cereus (BCC), and Staphylococcus aureus (SAC) counts, as well as tested for the incidence of Listeria monocytogenes (LM) and Salmonella (SALM) by standard plating methods. Bacterial populations attached to the cleaning and handling tools were observed by scanning electron microscopy (SEM). Ten selected gram-positive isolates were further analyzed by 16S rRNA sequence analysis and compared with isolates from filled baguettes and assorted salads. The floor mops consistently yielded the highest APCs, CCs, and ECs (5.7, 4.1, and 3.0 log CFU/g, respectively), while gloves had the lowest corresponding counts (3.6, 2.0, and 1.0 log CFU/g, respectively). Low BCCs and SACs were recorded in this study (ca. 1.2 log CFU/g), while SALM and LM were each detected in five cleaning tool samples. SEM showed rods and cocci attached to handling and cleaning tools. Furthermore, results of 16S rRNA sequence analysis indicated that several gram-positive isolates were identified as S. aureus, Staphylococcus pasteuri, Staphylococcus sciuri, and Enterococcus faecalis. Genetically similar strains (100% similarity) were isolated from cleaning and handling tools and associated ready-to-eat (RTE) foods. Cleaning and handling tools may act as reservoirs of contamination for RTE foods during preparation in retail delicatessens in South Africa. The transfer of potential pathogens, such as S. aureus, to foods from cleaning and handling tools may hold food safety implications.     

Weight concerns and cognitive style: which carries more "weight" in the prediction of smoking among college women?

Although weight concerns and smoking are related, anorexic and bulimic women, both of whom have elevated weight concerns, have significant differences in smoking status. Fewer anorexic women smoke, compared with bulimic women, suggesting that weight concerns do not fully explain smoking status. This study investigated the contribution of one factor, cognitive style, to differences in smoking status among college women with different levels of weight concerns: Anorexic tendencies (n = 47), bulimic tendencies (n = 62), weight concerns (n = 56), and no weight concerns (n = 76). Nearly 47% of women with bulimic tendencies, 37.5% of women with weight concerns, and 27.7% of women with anorexic tendencies were current smokers. A total of 22% of women without weight concerns were current smokers. A logistic regression model revealed that race, age, the Personal Standards subscale of the Frost Multidimensional Perfectionism Scale, the Self-Control and Self-Esteem subscale of the Brief Mizes Anorectic Cognitions Questionnaire, and membership in the bulimic tendencies category were significant independent predictors of smoking status. Both weight concerns and cognitive-style variables, including perfectionism and self-control, carried "weight" in the prediction of smoking among college women. In light of these findings, treatment research should explore both the behavioral and cognitive factors associated with weight-concerned college smokers.     

A method for reproducibly preparing synthetic nanopores for resistive-pulse biosensors

There is increasing interest in using nanopores in synthetic membranes as resistive‐pulse sensors for biomedical analytes. Analytes detected with prototype artificial‐nanopore biosensors include drugs, DNA, proteins, and viruses. This field is, however, currently in its infancy. A key question that must be addressed in order for such sensors to progress from an interesting laboratory experiment to practical devices is: Can the artificial‐nanopore sensing element be reproducibly prepared? We have been evaluating sensors that employ a conically shaped nanopore prepared by the track‐etch method as the sensor element. We describe here a new two‐step pore‐etching procedure that allows for good reproducibility in nanopore fabrication. In addition, we describe a simple mathematical model that allows us to predict the characteristics of the pore produced given the experimental parameters of the two‐step etch. This method and model constitute important steps toward developing practical, real‐world, artificial‐nanopore biosensors.     

Polymer grafting from CdS quantum dots via AGET ATRP in miniemulsion

We report the synthesis of CdS quantum dot (QD)-poly(acrylate) nanocomposites using a recently developed catalytic system where activators are generated by electron transfer for atom-transfer radical polymerization (ATRP) in a miniemulsion. The QD surface was functionalized with a tris(alkyl)phosphine, previously modified with an ATRP chlorine initiator, and subsequent controlled polymerization was carried out from the functionalized surface of nanoparticles. The final material showed a high homogeneity and the QDs were evenly dispersed. The optical-absorption edge in the visible spectra of the nanocomposites attests the presence of the CdS QDs. Quantum confinement effects were assigned, though a blue shift in relation to the optical spectrum of the initial QDs has been observed.     

DFB semiconductor diode laser frequency stabilization employingelectronic feedback and Bragg grating Fabry-Perot interferometer

A method for stabilizing the center frequency drift of a diode laser is described. The method employs electronic feedback of the frequency error signal and utilizes an in-fiber Bragg grating Fabry-Perot interferometer as a frequency discriminator. The measured standard deviation of the frequency drift of the heterodyne beat signal of two lasers was less than 16 MHz in a time of 2.5 h     

Long-term repetition priming of briefly identified objects.

The authors provide evidence that long-term memory encoding can occur for briefly viewed objects in a rapid serial visual presentation list, contrary to claims that the brief presentation and quick succession of objects prevent encoding by disrupting a memory consolidation process that requires hundreds of milliseconds of uninterrupted processing. Subjects performed a search task in which each item was presented for only 75 ms. Nontargets from the search task generated priming on 2 subsequent indirect memory tests: a search task and a task requiring identification of visually masked objects. Additional experiments revealed that information encoded into memory for these nontargets included perceptual and conceptual components, and that these results were not due to subjects maintaining items in working memory during list presentation. These results are consistent with recent neurophysiological evidence showing that stimulus processing can occur at later stages in the cognitive system even when a subsequent new stimulus is presented that initiates processing at earlier stages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging increases CD8 T cell apoptosis induced by hyperstimulation but decreases apoptosis induced by agonist withdrawal in mice

OBJECTIVE: To describe the innovative programs of three health maintenance organizations (HMOs) for providing primary care for long-stay nursing home (NH) residents and to compare this care with that of fee-for-service (FFS) residents at the same NHs. DESIGN: Cross-sectional interviews and case-studies, including retrospective chart reviews for 1 year. SETTING: The programs were based in 20 community-based nursing homes in three regions (East, West, Far West). PARTICIPANTS: Administrative and professional staff of HMOs in three regions and 20 NHs; 215 HMO and 187 FFS residents at these homes were studied. MAIN OUTCOME MEASURES: Emergency department (ED) and hospital utilization. RESULTS: All HMO programs utilized nurse practitioner/physician's assistants (NP/PA), but the structural configuration of physicians' (MD) practices differed substantially. At nursing homes within each region, all three HMO programs provided more total (MD plus NP/PA) visits per month than did FFS care (2.0 vs 1.1, 1.3 vs .6, and 1.4 vs .8 visits per month; all P < .05). The HMO that provided the most total visits had a significantly lower percentage of residents transferred to EDs (6% vs 16%, P = .048), fewer ED visits per resident (0.1 vs .4 per year, P = .027), and fewer hospitalizations per resident (0.1 vs .5 per year, P = .038) than FFS residents; these differences remained significant in multivariate analyses. However, the other two programs did not achieve the same benefits on healthcare utilization. CONCLUSIONS: HMO programs for NH residents provide more primary care and have the potential to reduce ED and hospital use compared with FFS care. However, not all programs have been associated with decreased ED and hospital utilization, perhaps because of differences in structure or implementation problems.     

Elimination lineups: An improved identification procedure for child eyewitnesses.

Elimination lineup procedures were proposed that required the witness to eliminate all but 1 lineup member before being asked if the remaining lineup member was the criminal. Elimination lineups were designed and tested with the aim of reducing false-positive choices by child eyewitnesses (n?=?587 children, 10–14 years, M?=?12 years; n?=?185 adults). Elimination lineups decreased false-positive responding in children without significantly reducing correct identifications. Fast elimination lineups with modified instructions emphasizing the negative consequences of identifying an innocent person and explaining how to make an absolute judgment significantly decreased children's false-positive rate to a level comparable with adults shown a simultaneous lineup. The potential benefits of elimination lineup procedures for child witnesses are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The application of synthetic fluids to automotive lubricant development: Trends today and tomorrow

Engineering design of the internal combustion engine is under a constant state of evolution which has been driven by many factors. These design changes have led to higher performance requirements from the lubricant, e.g. greater resistance to thermal and oxidative degradation, improved deposit and sludge control, and increased control of volatility. Mineralbased lubricants have traditionally proved successful for the vast majority of automotive applications. The current advances have stretched such products to the limit of their capabilities. In such areas, it has been found that synthetic lubricants offer benefits far outweighing their higher costs, providing clearcut performance benefits for the modern generation of higher-performance vehicles. The current state of the art is reviewed from both application and chemical standpoints, and future trends are projected in the light of ongoing developments.