Latent inhibition in rats is abolished by NMDA-induced neuronal loss in the retrohippocampal region, but this lesion effect can be prevented by systemic haloperidol treatment.

Latent inhibition (LI) refers to the retardation in learning about the significance of a neutral stimulus that results from its nonreinforced preexposure. There is evidence that electrolytic or aspiration lesions of the hippocampal formation can disrupt LI (I. Weiner, see record 1991-06652-001). It has been suggested that this effect may stem from the interruption of a projection from the retrohippocampal region to the nucleus accumbens (A. J. M. Clark et al, 1992). The present experiment assessed this possibility by comparing LI in rats with retrohippocampal N-methyl-D-aspartate (NMDA) lesions extending from the entorhinal cortex to the ventral subiculum to that seen in vehicle controls and unoperated controls. LI was abolished by the retrohippocampal lesion. The effect of the lesion on LI was prevented by treatment with systemic haloperidol (0.2 mg/kg). The results are discussed with respect to an animal model of schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A role for dorsal and ventral hippocampus in inter-temporal choice cost-benefit decision making.

Previous studies suggest a preferential role for dorsal hippocampus (dHPC) in spatial memory tasks, whereas ventral hippocampus (vHPC) has been implicated in aspects of fear and/or anxiety. In this study, we tested the hypothesis that vHPC may be a critical subregion for performance on a delay-based, cost-benefit decision making task. Rats chose between the two goal arms of a T maze, one containing an immediately available small reward, the other containing a larger reward that was only accessible after a delay. dHPC, vHPC, and complete hippocampal (cHPC) lesions all reduced choice of the delayed high reward (HR) in favor of the immediately available low reward (LR). The deficits were not due to a complete inability to remember which reward size was associated with which arm of the maze. When an equivalent 10-s delay was introduced in both goal arms, all rats chose the HR arm on nearly all trials. The deficit was, however, reinstated when the inequality was reintroduced. Our results suggest an important role for both dHPC and vHPC in the extended neural circuitry that underlies intertemporal choice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chain transfer of vegetable oil macromonomers in acrylic solution copolymerization

The use of vegetable oil macromonomers (VOMMs) as comonomers in emulsion polymerization enables good film coalescence without the use of solvents that constitute volatile organic compounds (VOCs). VOMMs are derived from renewable resources and offer the potential of post‐application crosslinking via auto‐oxidation. However, chain transfer reactions of VOMMs with initiator and/or polymer radicals during emulsion polymerization reduce the amount of allylic hydrogen atoms available for primary auto‐oxidation during drying. Vegetable oils and derivatives were reacted with butyl acrylate and methyl methacrylate via solution polymerization, and the polymerization was monitored using in situ infrared spectroscopy to determine the extent of chain transfer. ¹H NMR spectroscopy was used to determine the loci of chain transfer and the molecular weight characteristics of the polymers were characterized by SEC. Solution polymerization was utilized because this limited temperature fluctuations and insolubility of the polymer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of acid value on the esterification mechanism of maleinized soybean oil with cotton

Aqueous solutions of maleinized soybean oil (MSO) were evaluated as formaldehyde-free reagents for cellulosic textiles. The reactivity of cotton cellulose with MSO reagents (having acid values of 156 and 230?mg KOH/g) neutralized with aqueous ammonia, in excess of functional groups, was studied using diffuse reflectance infrared Fourier transform spectroscopy. The acid value of aqueous ammonia-neutralized MSO influenced the formation of protonated amide intermediates. Cyclic anhydride and protonated amide functional groups were identified as reaction intermediates, which resulted in carboxylic ester linkages between MSO and cellulose upon elevated temperature curing.     

Anxiolytic effects of cytotoxic hippocampal lesions in rats.

Rats with cytotoxic lesions of the hippocampus were given 3 anxiety tests: social interaction with a novel rat, the elevated zero-maze (a modification of the plus-maze), and hyponeophagia (eating familiar and novel foods in a novel place). Marked anxiolytic effects were seen in the social interaction and hyponeophagia tests, but not on the zero-maze. These results confirm and extend previous experiments that used traditional lesion techniques. The zero-maze result was consistent with other experiments using the plus-maze, in which intrahippocampal administrations of pharmacological agents were not anxiolytic, although variability in ethological tests may also be a factor. As the hyponeophagia test used an elevated apparatus, as in the zero- and plus-mazes, the lack of a lesion effect in the zero-maze was unlikely to have been due to an inability to relieve height-induced anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Treatment of Mg powder with carbonic acid and the effect of treatment variables and treated Mg ratios on coating performance in salt spray tests

Magnesium-rich primers (MgRPs) are known to exhibit excellent corrosion resistance during natural weathering due to the formation of a controlled and complex cathodic protective layer which includes but is not limited to changing combinations of magnesium metal, magnesium hydroxide, and magnesium carbonate each during film formation, cure, and environmental exposure. Pretreating Mg powder with carbonic acid before incorporation into coatings has been shown to enhance the corrosion resistance of MgRPs. In an earlier study, the conditions for treating Mg powder and the effects of variables such as time and the order of addition were evaluated to determine optimized treatment conditions. In this study, the treatment process was analyzed further to better understand the nature of the carbonation process and the effect of treatment variables on the overall corrosion protection process. Coatings prepared with different ratios of treated and untreated Mg were evaluated via ASTM B117 salt fog exposure to determine the optimized ratio of treated and untreated pigments for maximum corrosion protection.     

Estimation of ozone with total ozone portable spectroradiometer instruments. I. Theoretical model and error analysis

Inexpensive devices to measure solar UV irradiance are available to monitor atmospheric ozone, for example, total ozone portable spectroradiometers (TOPS instruments). A procedure to convert these measurements into ozone estimates is examined. For well-characterized filters with 7-nm FWHM bandpasses, the method provides ozone values (from 304- and 310-nm channels) with less than 0.4% error attributable to inversion of the theoretical model. Analysis of sensitivity to model assumptions and parameters yields estimates of ±3% bias in total ozone results with dependence on total ozone and path length. Unmodeled effects of atmospheric constituents and instrument components can result in additional ±2% errors.     

Differential effects on TNF alpha production by pharmacological agents with varying molecular sites of action

This study describes the activation conditions for tumor necrosis factor-alpha (TNF alpha) production in myelomonocytic U937 cells and human primary peripheral blood monocytes in response to lipopolysaccharide (LPS) and/or phorbol 12-myristate 13-acetate (PMA). PMA itself induced only low levels of TNF alpha production with delayed kinetics (e.g. 0.758 +/- 0.128 ng/ml from U937 cells after 48 h) while LPS induced greater levels of TNF alpha production in less time (e.g. 2.083 +/- 0.96 ng/ml from monocytes in 24 h). Pharmacological agents with various molecular sites of action were used to validate the two systems, with the protein serine-threonine kinase inhibitors staurosporine and Ro-31-8220, the protein tyrosine kinase inhibitor herbimycin A (HBA) and dexamethasone exhibiting the greatest potency (IC50S 5-350 nM). In contrast to the effect on TNF alpha production, PMA induced strong phosphorylation/activation of p42/p44mapk in monocytes by 10 min determined in a mobility shift assay, while LPS was a weaker inducer. Additionally, staurosporine (to LPS and PMA) and HBA (to LPS only) inhibited the activation of these mitogen-activated protein kinase (MAPK) isoforms at doses 10-100 fold higher than those required to inhibit maximal TNF alpha production. These data indicate the involvement of the p42/p44mapk signalling pathway in LPS-induced pro-inflammatory cytokine production but suggest that other signalling pathways are also implicated in this phenomenon.     

Cytotoxic lesions of the retrohippocampal region attenuate latent inhibition but spare the partial reinforcement extinction effect

The study focuses on the use of brainstorming tool for consensual decision making in nursing services. A qualitative research has been developed with focus group technique use involving 6 workers from a basic health unit in Joao Pessoa city which belongs to the state network of Paraíba State Health Secretary. The results showed the method application plausibility as a strategy to nursing services quality improvement.     

Conditional discriminations based on external and internal cues in rats with cytotoxic hippocampal lesions.

Septal-hippocampal system lesions, mostly using aspiration techniques, have been reported to impair performance of conditional tasks. Rats with axon-sparing cytotoxic, hippocampal lesions were therefore tested in a range of instrumental conditional paradigms. They did not differ from controls in their ability to choose the appropriate object in a conditional object discrimination cued by internal state (hunger or thirst) or on performance of conditional visuospatial object discriminations. Acquisition of a conditional visuospatial discrimination with black and white boxes as stimuli was also unimpaired. In contrast, lesioned rats were profoundly impaired on an open T-maze task when cued by either their internal state (reference memory task) or their previous response (working memory task). The results indicate that perception or use of spatial cues, rather than conditional responding per se, is impaired by cytotoxic hippocampal lesions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)