The amygdala and development of social cognition: Theoretical comment on Bauman, Toscano, Mason, Lavenex, and Amaral (2006).

Nonhuman primate studies, using selective amygdala lesions that spare cortical areas and fibers of passage, have helped to clarify the amygdala's specific contribution to social and emotional behavior. M. D. Bauman, J. E. Toscano, W. A. Mason, P. Lavenex, and D. G. Amaral (2006; see record 2006-09890-001) reported that macaque monkeys (Macaca mulatta) with neonatal neurotoxic amygdala lesions displayed lower rank in social dominance status, reduced aggressive gestures, and enhanced fearful reactions to social cues compared with normal controls and those with neonatal hippocampal lesions when tested as juveniles in a group of peers. These results are discussed in light of a recent study (C. J. Machado & J. Bachevalier, 2006; see record 2006-09890-002) showing that the same selective amygdala damage in adolescent monkeys did not alter presurgical social dominance status. This variability in behavioral changes after selective amygdala lesions underscores the significant interplay between timing of the lesion, genetic traits, and environmental factors and suggests that the amygdala is not the generator of specific emotional responses, but acts as a modulator to ensure that emotional responses are appropriate to the external stimuli and social context. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.     

Tensile and water barrier properties of cassava starch composite films reinforced by synthetic zeolite and beidellite

Composites films were prepared by the casting method using native cassava starch plasticized with glycerol and 3D or 2D synthetic fillers i.e. Beta zeolite and Na-beidellite type 2:1 phyllosilicate. Special attention was paid to the effect of the filler contents and type on the mechanical and barrier properties. It was shown that films reinforced with lyophilized Beta zeolite presented both high water solubility (WS) and water vapor permeability (WVP) values than the pristine starch whereas an improvement on the WVP was found for composites prepared from Na-beidellite or from non lyophilized Beta zeolite. For the two types of fillers, a drastic increase of the mechanical properties (especially in the Young’s modulus) was observed.     

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)     

Quantification of allyl hexanoate in pineapple beverages and yogurts as a case study to characterise a source of uncertainty in dietary exposure assessment to flavouring substances

One source of uncertainty in the estimation of dietary exposure to flavouring substances is the uncertainty in the occurrence and concentration levels of these substances naturally present or added to foodstuffs. The aim of this study was to assess the variability of concentration levels of allyl hexanoate, considered as a case study, in two main food categories to which it is often added: pineapple juice-based beverages and yogurts containing pineapple. Thirty-four beverages and 29 yogurts, with pineapple fruit or juice and added flavourings declared as ingredients on the package, were purchased from the local market (in Rome) and analysed. Analytical methods based on the stir bar sorptive extraction (SBSE) technique for the isolation of the target analyte, and on GC-MS analysis for final determination, were developed for the two food categories. In beverages, allyl hexanoate concentrations ranged from less than 0.01 to 16.71 mg l(-1), whereas in yogurts they ranged from 0.02 to 89.41 mg kg(-1). Average concentrations in beverages and yogurts with pineapple as the main fruit ingredient (1.91 mg l(-1) for beverages, 9.61 mg kg(-1) for yogurts) were in fair agreement with average use level data reported from industry surveys for the relevant food categories (4.5 and 6.0 mg kg(-1), respectively). Within the group of yogurts a single product was found to contain a level of allyl hexanoate more than 10-fold higher than the average reported use level. The screening techniques developed by the European Food Safety Authority (EFSA) using use level data provided by industry gave estimates of exposure that were of the same order of magnitude as the estimates obtained for regular consumers who would be loyal to the pineapple yogurt and beverage products containing the highest observed concentration of the substance of interest. In this specific case the uncertainty in the results obtained with the use of standard screening techniques for exposure assessment based on industry reported use levels is low.     

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.     

One-step synthesis and solvent-induced exfoliation of hybrid organic-inorganic phyllosilicate-like materials

A room-temperature sol-gel-based process was used to produce by direct synthesis talc-like organosilicates having hexadecyl or aminopropyl groups pending in the interlayer space. Thermal analyses, Fourier transform infrared and 13C/29Si solid-state nuclear magnetic resonance spectroscopies confirmed the presence of organic moieties bonded to the inorganic network. Exfoliation of these organoclays in polar solvents such as water for the positively charged magnesium phyllo(aminopropyl)silicate, and in low polar solvents such as toluene and chloroform for hydrophobic magnesium phyllo(hexadecyl)silicate, was investigated by TEM. The ability of these layered magnesium organosilicates to exfoliate in appropriate solvents was exploited for the preparation of transparent self-supporting films and ordered macroporous networks using by latex colloidal crystal templates.     

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.