Inactivation of Listeria monocytogenes on frankfurters by monocaprylin alone or in combination with acetic acid

The antilisterial activity of monocaprylin (MC) and its combination with acetic acid (AA) on frankfurters was investigated. Each frankfurter was surface inoculated with a three-strain mixture of Listeria monocytogenes to obtain an inoculation level of 4.0 log CFU per frankfurter, and then dipped for 35 s in sterile deionized water (45 or 50 degrees C) containing 1% ethanol (control), 50 mM MC plus 1% ethanol, 1% AA plus 1% ethanol, or 50 mM MC plus 1% AA plus 1% ethanol. Samples were vacuum packaged, stored at 4 degrees C for 77 days, and analyzed for L. monocytogenes. Sensory odor and color of frankfurters were evaluated using a 9-point hedonic scale. Color was also objectively measured using the Minolta Chroma Meter. From day 0 to day 77, population counts of L. monocytogenes on frankfurters dipped in antimicrobial solutions at 50 degrees C were consistently lower than the control counts. Similar results were observed for samples treated at 45 degrees C. However, L. monocytogenes grew readily on control samples at both temperatures. Dipping of frankfurters in antimicrobial solutions (45 or 50 degrees C) significantly reduced (P < 0.05) the populations of L. monocytogenes. After 70 days of storage, L. monocytogenes was completely killed in samples dipped in MC+AA solution at 50 degrees C. The antimicrobial treatments did not affect the odor or color of the samples (P > 0.05). Overall, results indicated that dipping of frankfurters with MC reduced L. monocytogenes, and inclusion of AA further enhanced MC antilisterial activity, without any negative effect on odor or color.     

United States pharmacopeia safety evaluation of spirulina

The Dietary Supplements Information Expert Committee (DSI-EC) of the United States Pharmacopeial Convention (USP) reviews the safety of dietary supplements and dietary supplement ingredients for the purpose of determining whether they should be admitted as quality monographs into the United States Pharmacopeia and National Formulary (USP-NF). The United States Food and Drug Administration (FDA) has enforcement authority to pursue a misbranding action in those instances where a dietary supplement product indicates that it conforms to USP standards but fails to so conform. Recently DSI-EC undertook a safety evaluation of spirulina, a widely used dietary ingredient. DSI-EC reviewed information from human clinical trials, animal studies, and regulatory and pharmacopeial sources and analyzed 31 adverse event reports regarding spirulina to assess potential health concerns. At the conclusion of this review, DSI-EC assigned a Class A safety rating for Spirulina maxima and S. platensis, thereby permitting the admission of quality monographs for these dietary supplement ingredients in USP-NF. DSI-EC continually monitors reports concerning the safety of dietary supplements and dietary supplement ingredients for which USP dietary supplement monographs are developed. The DSI-EC may revisit the safety classification of spirulina as new information on this dietary ingredient becomes available.     

Lubrication of poly(vinyl alcohol) chain orientation by carbon nano‐chips in composite tapes

The extraordinary structural properties of graphene and carbon nanotube materials motivate the development of practical methods for their use in fabricating continuous, strong, and tough composite fibers. Poly(vinyl alcohol) (PVA)/carbon nano‐chip fiber (CNCF) composite tapes with 0.5 wt % loading show that Young's modulus, tensile strength, and toughness are increased by 585%, 653%, and 20%, respectively as compared to the control (PVA) tapes. Nano‐chips exfoliated from the CNCF during processing, lubricate polymer chain alignment, and orientation during drawing, where composite tapes could be drawn to higher draw ratios compared with the control tapes. As a result, the Herman's orientation factor (f) increased from 0.5 (control tape) to 0.8 (composite tape). Theoretical analysis shows ～ 16 vol % of the composite tapes consists of fully oriented PVA chains, which contributes to its exceptional mechanical performance. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Structure-preserving fixation allows scanning electron microscopy to reveal biofilm microstructure and interactions with immune cells

Pseudomonas aeruginosa is a pathogen that forms robust biofilms which are commonly associated with chronic infections and cannot be successfully cleared by the immune system. Neutrophils, the most common white blood cells, target infections with pathogen-killing mechanisms that are rendered largely ineffective by the protective physicochemical structure of a biofilm. Visualisation of the complex interactions between immune cells and biofilms will advance understanding of how biofilms evade the immune system and could aid in developing treatment methods that promote immune clearance with minimal harm to the host. Scanning electron microscopy (SEM) distinguishes itself as a powerful, high-resolution tool for obtaining strikingly clear and detailed topographical images. However, taking full advantage of SEM's potential for high-resolution imaging requires that the fixation process simultaneously preserve both intricate biofilm architecture and the morphologies and structural signatures characterising neutrophils responses at an infection site. Standard aldehyde-based fixation techniques result in significant loss of biofilm matrix material and morphologies of responding immune cells, thereby obscuring the details of immune interactions with the biofilm matrix. Here we show an improved fixation technique using the cationic dye alcian blue to preserve and visualise neutrophil interactions with the three-dimensional architecture of P. aeruginosa biofilms. We also demonstrate that this technique better preserves structures of biofilms grown from two other bacterial species, Klebsiella pneumoniae and Burkholderia thailandensis.     

Attention constraints of semantic activation during visual word recognition.

The reduction of semantic priming following letter search of the prime suggests that semantic activation can be blocked if attention is allocated to the letter level during word processing. Is this true even for the very fast-acting component of semantic activation? To test this, the authors explored semantic priming of lexical decision at stimulus onset asynchronies (SOAs) of either 200 or 1000 ms. Following semantic prime processing, priming occurred at both SOAs. In contrast, no priming occurred at the long SOA following letter-level processing. Of greatest interest, at the short SOA there was priming following the less demanding consonant/vowel task but not following the more attention-demanding letter search task. Hence, semantic activation can occur even when attention is directed to the letter level, provided there are sufficient resources to support this activation. The authors conclude that the default setting during word recognition is for fast-acting activation of the semantic system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using c-Fos immunocytochemistry to identify forebrain regions that may inhibit maternal behavior in rats.

Evidence indicates there is a neural system that inhibits maternal behavior in virgin rats. It has been suggested that pregnancy hormones promote the onset of maternal behavior by reducing the behavioral influence of this system. The authors used c-Fos immunocytochemistry to identify brain regions more activated by pup exposure in nonmaternal rats than in maternal rats. Previous experiments indicated that some of these regions, such as the posterodorsal medial amygdala and several medial hypothalamic sites, inhibit maternal behavior. For others, such as the ventral lateral septum, dorsal premammillary nucleus, and principal bed nucleus of the stria terminalis, this is the first indication that they could also inhibit maternal responding. These regions have previously been implicated in promoting defensive behaviors, consistent with the finding that nonmaternal rats actively avoid pups. These findings suggest the existence of a neural circuit through which pup exposure could promote defensive responses in virgin rats, and how pregnancy hormones could reduce such activity to stimulate maternal behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acquisition of drug self-administration: Environmental and pharmacological interventions.

The development of drug-reinforced behavior is a transition process characterized by a relatively rapid shift from little or no drug-maintained responding to high, stable levels of responding. Animal studies of drug self-administration focus on how rapidly this process takes place or what percentage of animals acquire drug self-administration. It is essential to have animal models of acquisition because the process is difficult to study with drug-naive humans. Animal studies reveal a wide range of factors that can either accelerate or decrease acquisition of drug self-administration, such as environmental conditions (e.g., feeding conditions, palatable dietary substances, stress), pharmacological variables (e.g., drug dose, drug history, pretreatment drugs), and individual differences (e.g., reactivity level, age, sex, dietary preferences, genetics). This article discusses the methods used to study acquisition of drug-reinforced behavior in laboratory animals and the variables that have been reported to accelerate or prevent the acquisition of drug-reinforced behavior. An understanding of the conditions that can enhance acquisition in animals may help predict vulnerability to drug use in humans and lead to successful methods for prevention of drug abuse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Field Evaluation of a Proprietary Storm-Water Treatment System: Removal Efficiency and Relationships to Peak Flow, Season, and Dry Time

A proprietary storm-water treatment system (Baysaver 1/2?K) was monitored as part of a low impact development project to assess pollutant removal efficiency and to model removal as a function of flow rate, season, and dry time. Twenty six storm events were sampled over a 12-month period and analyzed for total suspended solids, turbidity, conductivity, ammonia/ammonium, nitrate/nitrite, total phosphorus, total Zn, total Pb, and total Cu. The data were analyzed to determine which parameters showed significant removal by the device and whether or not the removal efficiencies were influenced by peak flow rate, season of the year, and/or dry time. Results indicated that the removal of each pollutant analyzed was statistically significant with the exception of conductivity, which showed higher outflow levels resulting in significant release of ions. Regression analyses revealed that all pollutants except for conductivity and total phosphorus showed significant negative relationships to peak flow rate and that conductivity and total Cu reductions were significantly related to the season of the year.     

Daily negative mood affects fasting glucose in Type 2 diabetes.

Objective: To examine the relationship between mood and blood glucose in a 21-day daily diary study. Design: During a home visit, information was gathered from 206 persons with Type 2 diabetes regarding demographics, disease characteristics and treatment, and depressive symptoms. They had blood drawn at a laboratory, yielding HbA1C. The participants were then telephoned each evening for 21 days and were asked about their positive and negative mood during the past 24 hours. They also tested their blood glucose upon rising in the morning. Main Outcome Measures: The main outcomes measures were positive and negative affect and fasting glucose. Results: Multilevel analyses revealed a relationship between negative affect on one day and morning glucose on the next day. There was no such relationship between positive affect and glucose, nor was there a comparable effect of glucose on one day and either positive or negative affect on the next day. Conclusion: The observed relationship between mood and blood glucose appears to be because of negative affect, not positive, with no evidence of a lagged effect of glucose on mood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)