Oxidation Rates of Triacylglycerol and Ethyl Ester Fish Oils

Fish oil is available primarily as triacylglycerols (TAG) or ethyl esters (EE). Anecdotal evidence suggests that TAG have superior bioavailability and oxidative stability compared to EE. In this work, peroxide value (PV) and p‐anisidine value (AV) were used to monitor oxidation in commercially available TAG and EE fish oils incubated at temperatures from 5 to 60 °C. Pseudo first‐order kinetics were assumed and rate constants were calculated for each temperature. At all temperatures, the rates of oxidation were higher for EE oils than TAG oils. For PV and AV measured in both oils, non‐linear Arrhenius models were plotted, generating activation energies that ranged from 7 to 103 and 2 to 159 kJ/mol for PV and AV, respectively. Although TAG were more resistant to oxidation than EE, they had lower activation energies (E_a) at ≤15 °C for reactions measured with PV and AV. The E_a for EE was negative at temperatures ≥45 °C, indicating that reaction rate was influenced by factors in addition to temperature.     

Cognitive status impacts age-related changes in attention to novel and target events in normal adults.

In this study, the authors investigated the relationship between the cognitive status of normal adults and age-related changes in attention to novel and target events. Old, middle-age, and young subjects, divided into cognitively high and cognitively average performing groups, viewed repetitive standard stimuli, infrequent target stimuli, and unique novel visual stimuli. Subjects controlled viewing duration by a button press that led to the onset of the next stimulus. They also responded to targets by pressing a foot pedal. The amount of time spent looking at different kinds of stimuli served as a measure of visual attention and exploratory activity. Cognitively high performers spent more time viewing novel stimuli than cognitively average performers. The magnitude of the difference between cognitively high and cognitively average performing groups was largest among old subjects. Cognitively average performers had slower and less accurate responses to targets than cognitively high performers. The results provide strong evidence that the link between engagement by novelty and higher cognitive performance increases with age. Moreover, the results support the notion of there being different patterns of normal cognitive aging and the need to identify the factors that influence them. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Accuracy, confidence, and calibration: How young children and adults assess credibility.

Do children and adults use the same cues to judge whether someone is a reliable source of information? In 4 experiments, we investigated whether children (ages 5 and 6) and adults used information regarding accuracy, confidence, and calibration (i.e., how well an informant's confidence predicts the likelihood of being correct) to judge informants' credibility. We found that both children and adults used information about confidence and accuracy to judge credibility; however, only adults used information about informants' calibration. Adults discredited informants who exhibited poor calibration, but children did not. Requiring adult participants to complete a secondary task while evaluating informants' credibility impaired their ability to make use of calibration information. Thus, children and adults may differ in how they infer credibility because of the cognitive demands of using calibration. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Accessibility of local government websites: influence of financial resources,county characteristics and local demographics

Universal Access in the Information Society - Although many studies have investigated how well government websites have implemented website accessibility standards, such as Section 508 and...     

The impact of intermediate‐head navigation locks on downstream fish passage

Navigation in inland waterways is increasingly important worldwide and so is inherently the construction and use of navigation locks. However, the impact of navigation locks on downstream migrating fish is rarely documented. In Belgium, the Albert Canal connecting the Meuse River to the Scheldt Estuary may offer migration opportunities for European eel (Anguilla anguilla) and Atlantic salmon (Salmo salar), two critically endangered species. During their downstream migration phase (respectively silver eels and salmon smolts), both species have to pass five intermediate‐head navigation locks before reaching the estuary. Previous research showed that silver eel escapement is largely unsuccessful and that eels are delayed extensively at the navigation lock complexes. To get a better understanding of the mechanisms behind these failures and delays, we tagged and released 62 silver eels and 44 salmon smolts in the vicinity of one navigation lock complex of the canal. This paper reports the mechanisms behind the previously perceived delay, the route choices to pass the complex, and the risks involved. Of the 65% tagged eels and 73% tagged smolts that succeeded to pass the complex, respectively, 20% and 41% needed more than one trial to pass the complex. Moreover, 52% of all trials were via intakes of the lock filling system, at least four smolts (17%) died after intake passing, and about 30% of both intake‐passing smolts and eels stopped migrating after passage. Therefore, intermediate‐head navigation locks are a potential threat to downstream migrating fish, which requires more research to fully investigate its impact.     

The effects of stoichiometry on the properties of exsolved Ni-Fe alloy nanoparticles for dry methane reforming

The dry reforming of methane has received notable attention as a chemical process to convert natural gas into value-added chemicals and fuels. Ni-based exsolution catalysts using perovskite oxides supports have been used for their attractive sinter-resistance and coke-resistance properties. The perovskite oxide in itself has unique defect chemistry that can be used to manipulate and control the properties of the catalyst nanoparticles exsolved on the surface, therefore influencing both the nanoparticle and support characteristics. In this study, the La:Fe ratio of Ni-doped LaFeO₃ was used to manipulate and control the properties of exsolved Ni-Fe alloy nanoparticles. The Ni-Fe nanoparticles consisted of different sizes ranging from 10 to 380 nm. Temperature programmed surface reaction studies along with materials characterization with SEM, STEM-HAADF, XRD, and BET showed that the Ni-Fe nanoparticles from different solid precursors have the same active sites for methane activation but differ in performance and stability because of size effects, metal-support strength, composition and support basicity. A mechanism is proposed to decipher the merits of the Ni-Fe nanoparticles with the best activity, selectivity, and stability in this study.     

Not “capitalizing” on social capitalization interactions: The role of attachment insecurity.

Capitalization interactions, in which partners share positive events, typically produce positive relationship outcomes (Gable, Gonzaga, & Strachman, 2006). However, the limiting conditions of these interactions have not been examined. In this study, 101 dating couples discussed a positive event in the life of each partner. Ratings of perceived responsiveness were made by both the romantic partner who disclosed a positive event and his/her responding partner. Trained observers then rated each videotaped interaction. More avoidantly attached responders reported being and were rated by coders as less responsive, particularly if their disclosing partners were more anxiously attached. Avoidantly attached individuals also underestimated their partners' responsiveness relative to observer ratings. Anxious responders underestimated their own responsiveness when their disclosing partners were more avoidantly attached. These results indicate that insecurely attached individuals are relatively less likely to be responsive and to perceive responsiveness in capitalization interactions than are more securely attached individuals. This is especially true when highly anxious and highly avoidant individuals are relationship partners. (PsycINFO Database Record (c) 2011 APA, all rights reserved)