Hippocampal and prefrontal cortex contributions to learning and memory: Analysis of lesion and aging effects on maze learning in rats.

Young adult rats with bilateral lesions to the hippocampus or prefrontal cortex, young operated controls, and normal old rats were tested on two complex mazes in the Hebb–Williams series. Approximately half the animals were previously trained on one of the mazes; the remainder received no previous training. The trained hippocampal rats showed sparing of memory for the general skill of maze learning but poor recall of the specific maze on which they had been previously trained. The opposite pattern was observed in trained prefrontal rats. In contrast, the aged rats' memory for maze-specific and maze-general information was impaired. The results confirmed the importance of the hippocampus for recalling highly specific information and pointed to a possible role for the frontal lobes in learning and remembering nonspecific skill-related information. The generalized deficit of the aged rats indicates that both types of memory were compromised and offers further evidence of frontal lobe and hippocampal dysfunction in normal aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Risk evaluation for federally listed (roseate tern,piping plover) or candidate (red knot) bird species in offshore waters: A first step for managing the potential impacts of wind facility development on the Atlantic Outer Continental Shelf

With a worldwide increase in attention toward developing a reliance on renewable energy, there is a need to evaluate the effects of these facilities (solar, wind, hydropower) on ecosystems. We conduct a hazard and risk evaluation for three species of birds that are listed, or candidates for listing, as federally threatened or endangered in the US, and that might occur offshore on the Atlantic Outer Continental Shelf (AOCS) where wind power facilities could be developed. Our objectives were to: 1) provide conceptual models for exposure for each species, and 2) examine potential exposure and hazards of roseate tern (Sterna dougallii) and piping plover (Charadrius melodus, both federally endangered in the US) and red knot (Calidris canutus rufa, candidate species) in the AOCS. We used a weight-of-evidence approach to evaluate information from a review of technical literature. We developed conceptual models to examine the relative vulnerability of each species as a function of life stage and cycle (breeding, staging, migratory, wintering). These methods are useful for conducting environmental assessments when empirical data are insufficient for a full risk assessment. We determined that 1) Roseate terns are likely to be exposed to risk during the migratory and breeding season when they occur in the AOCS, as well as while staging. 2) Piping plovers are not likely to be at risk during the breeding season, but may be at risk during spring or fall migrations. Risk to this species is likely to be low from turbines located far from land as this species migrates mainly along the coast. 3) Red knots are potentially exposed to some risk during migration, especially long-distance migrants whose migratory routes take them over the AOCS. More information is required on exact spatio-temporal migration routes, flight altitudes (especially during ascent and descent), and behavioral avoidance of turbines by birds to ascertain their risk.     

Characterization of the phytochemicals and antioxidant properties of extracts from Teaw (Cratoxylum formosum Dyer)

The leaves of the Thai vegetable, Teaw (Cratoxylum formosum Dyer) were extracted with ethanol to provide an extract that had antioxidant properties. The composition of the extract was studied by high-performance liquid chromatography with a diode array detector, and by electrospray ionization mass spectrometry. The main antioxidant component (peak 1) was chlorogenic acid, which was present at 60% of the extract. Three minor components were present at 7%, 3% and 2%, and other components that were present at lower concentrations were also observed. Treatment of the Teaw extract with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) caused a similar reduction in peak area of 55.2–58.1% for chlorogenic acid and the three minor components, indicating that these components had common structural features. Component 2 was identified as dicaffeoylquinic acid, and compounds 3 and 4 were identified as ferulic acid derivatives. The radical-scavenging activity of the Teaw extract was compared with -tocopherol, BHT and chlorogenic acid, using the DPPH and 2,2′-azinobis (3-ethylbenzothialozinesulfonic acid) radical cation (ABTS⁺) assays. The Teaw extract scavenged both free radicals more strongly than did -tocopherol and BHT, and the activity of the extract was consistent with the concentration of chlorogenic acid that was present, confirming that this component is a major contributor to the antioxidant activity. The acute toxicity of the Teaw leaf extract was investigated in mice, and it was found that the LD₅₀ of the extract was >32 g/kg. Consequently, this plant is a promising source of a natural food antioxidant.     

Effects of Juice Matrix and Pasteurization on Stability of Black Currant Anthocyanins during Storage

The effects of juice matrix and pasteurization on the stability of total phenols and especially total and individual anthocyanins were examined in black currant (BC) juice and mixtures with apple, persimmon, and peach juices at 4 °C and 20 °C. Total phenol content decreased in all juices at both temperatures but there was a trend to lower levels in unpasteurized over pasteurized juices. Differences in the decline of total anthocyanins between pasteurized and unpasteurized juices varied according to the juice type and the storage temperature. At 4 °C storage, anthocyanins declined in all juices according to pseudo 1st‐order kinetics and there were only small differences in the rates between pasteurized and unpasteurized juices. However, at 20 °C, although pasteurized and unpasteurized BC juices and pasteurized mixed juices followed pseudo 1st‐order kinetics, there was a different pattern in unpasteurized mixed juices; a rapid initial decline was followed by a slowing down. The effect of the added juice on anthocyanin decline was also different at either temperature. At 4 °C, the anthocyanins decreased faster in mixed juices than BC juice alone, but at 20 °C, at least in pasteurized mixed juices, the decline was similar or even slower than in BC juice; there were only small differences among the 3 mixed juices. At 20 °C, in pasteurized and unpasteurized BC juices, the rate of decrease was essentially the same for all 4 individual anthocyanins but in the mixed juices the 2 glucosides decreased significantly faster than the 2 rutinosides.     

Antioxidant and antimicrobial activities of tea infusions

Tea polyphenols, especially the catechins, are potent antimicrobial and antioxidant agents, with positive effects on human health. White tea is one of the less studied teas but the flavour is more accepted than that of green tea in Europe. The concentrations of various catechins in 13 different kinds of infusion were determined by capillary electrophoresis. The total polyphenol content (Folin–Ciocalteu method), the trolox equivalent antioxidant capacity (TEAC value determined with the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation) and the inhibitory effects of infusions on the growth of some microorganisms were determined. Five different infusions (black, white, green and red teas and rooibos infusion) were added to a model food system, comprising a sunflower oil-in-water emulsion containing 0% or 0.2% bovine serum albumin (BSA), and the oxidative stability was studied during storage at 37 °C. Oxidation of the oil was monitored by determination of the peroxide value.     

An overview of formation and roles of acetaldehyde in winemaking with emphasis on microbiological implications

Summary Acetaldehyde is an important aroma compound in wine. This article first reviews the microbial and chemical formation of acetaldehyde, then the effects of sulphur dioxide on acetaldehyde and effects of acetaldehyde on wine colour and physical stability are described briefly. Finally, the microbiological implications of acetaldehyde are emphasized with respect to practical significance in wine fermentation.     

Measurements of Thermal Diffusivity of Impurity-Helium Solids

Thermal diffusivity of the Kr- and N₂-impurity-helium solids (IHS) has been measured for the samples, immersed into liquid helium in the temperature range of 2.2–4.2 K. It has been found that the thermal diffusivity for both solids does not differ from that of liquid helium when the convection is absent even for the case when the samples were compact 10 times as compared to their initial volume. It should be emphasized that the presence of less than 0.5% mole fraction of a rare gas in the form of IHS allows us to suppress completely any convection in liquid helium (this effect was not observed when deuterium was used as an impurity). IHS can be used as a specific porous medium for investigations of critical phenomena of the He-I–He-II phase transition, as the He-aerogel systems.