What do Québec children eat during their first six months?

Study objectives were to describe the introduction of foods and beverages and the use of vitamin and/or mineral supplements among infants aged six months, and to identify factors associated with following Québec recommendations on introducing foods and beverages. Study subjects were primiparous women interviewed by phone when their infants were approximately six months old. Data were gathered on foods and beverages offered to infants, the age at which these were introduced, and supplements. The use of each food, beverage, and supplement was evaluated according to recommendations. Mean age at which foods were introduced and proportions of women who followed recommendations were calculated. Multivariate logistic regression models were used to identify the factors associated with following recommendations. Results indicated that among the 1,937 interviewed mothers, 212 (10.9%) exclusively breast-fed their infants before age four months, 1,073 (55.4%) breast-fed their infants at birth but gave them formula or foods before age four months, and 652 (33.7%) formula-fed their infants at birth. Factors associated with adherence to recommendations were breast-feeding exclusively, being older than 30 years, an annual family income of at least 60,000 dollars, and being a non-smoker. Few mothers followed all the recommendations.     

Very large-scale neighborhood search algorithms for the design of service overlay networks

Service Overlay Networks (SONs) allow virtual operators to create and deploy value-added Internet services with Quality of Service guarantees, while leaving the underlying network infrastructure unchanged. The deployment of a SON can be very expensive, and hence its planning requires careful decisions, including the overlay nodes’ placement and the capacity provisioning of the access links that connect the end-users to the SON infrastructure.     

Biodegradation of endocrine disrupting compounds in harbour seawater and sediments

The biodegradation of three endocrine disrupting compounds was examined using samples of seawater and sediment collected from Halifax Harbour, Nova Scotia, Canada, an urbanized harbour impacted by over two centuries of anthropogenic contamination. Flask experiments, where the samples were mixed to form a slurry were used to monitor the aerobic biodegradation of the synthetic plasticizer bisphenol A (BPA), the natural hormone 17β-estradiol (E2), and the pharmaceutical and contraceptive ethinylestradiol (EE2). Degradation rates followed the order E2 > EE2 > BPA with half-lives of up to 1, 5 and 14 days in seawater, respectively. A rapid initial degradation rate for all three compounds with no apparent lag phase indicated the ability of the microbial community to readily catabolise the chemicals. The formation of unidentified non-persistent intermediate metabolites was observed during the E2 degradation experiments. These degradation rates are more rapid and complete than reported in previous studies, indicating the adaptation of native microbial communities to these contaminants.     

Comparison of emotional responses in monkeys with rhinal cortex or amygdala lesions.

Four emotionally arousing stimuli were used to probe the behavior of monkeys with bilateral ablations of the entorhinal and perirhinal cortex. The monkeys' behavioral changes were then contrasted with those observed earlier (M. Meunier, J. Bachevalier, E. A. Murray, L. Málková, & M. Mishkin, 1999) in monkeys with either neurotoxic or aspiration lesions of the neighboring amygdala. Rhinal cortex ablations yielded several subtle behavioral changes but none of them resembled any of the disorders typically seen after amygdalectomies. The changes produced by rhinal damage took mainly the form of heightened defensiveness and attenuated submission and approach responses, that is, just the opposite of some of the most distinctive symptoms following amygdala damage. These findings raise the possibility that the rhinal cortex and amygdala have distinct, interactive functions in normal behavioral adaptation to affective stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A study of some alkali metal-furangraphite compounds and of their charge transfer characteristics

The reaction of furan on the 1st- to 6th-stage potassium-graphite compounds, as well as on some derivatives of other alkali metals, has been critically examined. The composition and the main structural features were determined and it is suggested that the formation of the ternary compound and the stage changes observed are intimately connected with a redistribution between the furan and the aromatic layers of the electron donated by the metal atom. The presence of the electron on the furan has two important consequences: an increase in the apparent volume of the molecules due to the fuzzy orbital occupied by the electron and to the repulsion between the charged species, and a long-term chemical instability of the ternary compound probably due to the presence of the electron on an antibonding orbital.     

High-throughput cytochrome P450 inhibition assays using laser diode thermal desorption-atmospheric pressure chemical ionization-tandem mass spectrometry

This paper describes the development of a high-throughput method for the analysis of cytochrome P450 (CYP) inhibition assay incubation samples using laser diode thermal desorption interfaced with atmospheric pressure chemical ionization mass spectrometry (LDTD-APCI-MS). Data for the CYP isoforms 3A4, 2D6, 2C9, and 1A2 from competitive inhibition assays are shown. The potential for inhibition of the CYP isoforms was measured by monitoring the level of the metabolites 6beta-hydroxytestosterone (3A4), dextrorphan (2D6), 4'-hydroxydiclofenac (2C9), and acetaminophen (1A2) formed in the presence of drug candidates using an eight-point titration. The analytical method involves plating of the inhibition samples on specially designed 96-well plates with stainless steel bottoms, followed by direct analysis using the LDTD source. Validation of the LDTD-MS method was performed by testing for interferences, reproducibility, dynamic range, ion suppression, and the ability of the source to produce comparable results to previously validated LC-MS methods. IC50 values for each CYP isoform using 33 different test compounds showed excellent agreement between LDTD-APCI-MS and LC-MS methods and literature values where available. Assay analysis time using the LDTD-APCI source is reduced to less than 30 min for a single 96-well plate compared to greater than 10 h using the LC-MS method. The LDTD-APCI-MS and LC-MS methods and results are compared and limitations and future potential for LDTD-APCI-MS are discussed.     

IR spectroscopy study of polypropylene natural aging

Structural modifications of a commercial polypropylene (PP) sample are studied by IR spectroscopy. Aging this sample under an ambient atmosphere with or without the presence of ambient light shows the oxidation process to be the most predominant. Spectral analysis reveals that the commercial sample is isotactic and also indicates that, for the new sample, oxygen establishes single bonds with carbon. However, through the aging process, spectral changes essentially occur in the regions of ∼3400, ∼1712, and 1170 cm⁻¹ which correspond to hydroxyl and/or hydroperoxide groups, a carbonyl group, and C O, respectively. The deconvolution of the bands corresponding to a carbonyl group reveals the presence of a complicated mixture of oxidation products: aldehydes, ketones, esters, acids, peresters, and peracids. Spectral analysis also shows that the most favorable site for oxidation is at the methylene group. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1742–1748, 2000     

Impact of amygdala, orbital frontal, or hippocampal lesions on threat avoidance and emotional reactivity in nonhuman primates.

The authors measured the effects of bilateral amygdaloid, orbital frontal, or hippocampal lesions on emotional reactivity and passive avoidance in rhesus monkeys (Macaca mulatta). Animals were presented with 8 neutral or 8 aversive objects, each paired with a highly preferred food reward. Sham-operated control animals displayed heightened defensive behaviors and typically would not approach or retrieve the food when paired with a potential predator (coiled rubber snake), 2 conditioned aversive stimuli for laboratory-housed monkeys (a capture net and leather handling gloves), and 1 object displaying a threatening social signal (direct eye contact from a human-like doll). Animals with amygdala lesions, but not hippocampal or orbital frontal lesions, showed less tension-related behaviors and diminished passive avoidance of the rubber snake and its matched neutral item (a coiled piece of hose) relative to control animals. All operated groups displayed normal patterns of behavior toward conditioned and socially aversive objects. These results expand our understanding of how the primate brain evaluates reward and threat, and indicate a highly specialized role for the amygdala in mediating passive avoidance and emotional reactivity to potentially life-threatening stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of Biobased Epoxy Matrices for the Preparation of Green Composite Materials for Civil Engineering Applications

Epoxy matrices are successfully used for structural strengthening in civil engineering applications by means of carbon fiber reinforced polymers (CFRPs). In the context of sustainable development, the aim of this study is to develop biobased epoxy matrices as an alternative to the traditional petroleum‐based epoxy matrices used in CFRPs. This study focuses on two biobased epoxy monomers: a diglycidyl ether of bisphenol A (DGEBA) and a sorbitol polyglycidyl ether (SPGE). These monomers are reacted with a biobased curing agent, a phenalkamine (PhA), derived from cardanol. After in‐depth characterization of the chemical structures of the three monomers, the reactivity of both systems, DGEBA‐PhA and SPGE‐PhA, is studied using differential scanning calorimetry and rheology. The properties of the networks are characterized via dynamic mechanical analysis and water uptake measurements for polymers with partial or full conversion of epoxy groups, which are obtained by crosslinking at room temperature or at high temperature, respectively. The results reveal that the two systems are good candidates for the preparation of green composite materials as they meet the requirements necessary for manufacturing composites in civil engineering applications.