Stability of Older Adults' Preferences for Life-Sustaining Medical Treatment.

The use of instructional advance directives assumes that preferences for life-sustaining medical treatment remain stable over time and across changes in life condition. A sample of 332 older adults recorded their preferences for 4 life-sustaining treatments in 9 illness scenarios. These preferences were elicited again 1 and 2 years after the original interview. Overall, preferences for life-sustaining treatment were moderately stable over time, but stability varied significantly across judgments. Preferences were most stable for illness scenarios that were most and least serious and for decisions to refuse treatment. Age, gender, education, and prior completion of an advance directive were all related to preference stability, and evidence indicated that declines in physical or psychological functioning resulted in decreased interest in life-sustaining treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Job Strain or Healthy Work: A Question of Task Design.

Objectively evaluated task requirements were used to classify jobs causing high strain, low strain, and jobs conducive to personal development. Effects of these job characteristics on psychophysiological outcomes were tested in 241 employees by using 24-hr ambulatory assessment of blood pressure (BP), heart rate, and mood. Self-reports about job characteristics showed that employees working in jobs conducive to personal development perceived the highest job demands and decision latitude. They also showed a healthy cardiovascular behavior with increased diastolic BP at work and its strong unwinding at night. Although self-reports about job characteristics did not differ between low- and high-strain jobs, employees exposed to high-strain jobs had higher systolic and diastolic BP during work and more often a disturbed relaxation ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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Calcium-induced membrane microdomains trigger plant phospholipase D activity

Plant alpha-type phospholipase D proteins are calcium-dependent, lipolytic enzymes. The morphology of the aggregates of their phospholipid substrate fundamentally defines the interaction between the enzyme and the surface. Here we demonstrate that the Ca(2+)-induced generation of membrane microdomains dramatically activates alpha-type phospholipase D from white cabbage. 500-fold stimulation was observed upon incorporation of 10 mol % 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate (POPA) into 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) vesicles in the presence of Ca(2+) ions. Enhanced association of PLDalpha2 with phospholipid surfaces containing anionic components was indicated by lag phase analysis and film balance measurements. Differential scanning calorimetry showed that the POPA-specific activation correlates with the phase behavior of the POPC/POPA vesicles in the presence of Ca(2+) ions. We conclude from the results that the Ca(2+)-induced formation of POPA microdomains is the crucial parameter that facilitates the binding of PLD to the phospholipid surface and suggest that this effect serves as a cellular switch for controlling PLD activity.     

Phospholipid Hydrolysis and Transphosphatidylation by Phospholipase D from Indian Mustard Seeds in Two-Phase Systems

Phospholipase D (PLD), isolated from Indian mustard seeds and purified to homogeneity, has recently been identified as typical α‐type PLD with a high activity toward phosphatidylcholine (PC) in an aqueous mixed micellar system (Khatoon et al. 2014, Phytochemistry 117, 65–75). In light of biocatalytical application, we have now studied the enzyme in aqueous‐organic two‐phase systems and compared the results with the properties of the enzyme in aqueous mixed micellar systems. n‐Hexane containing 5–10 mol% of 1‐ or 2‐octanol proved to be optimal as an organic solvent in the two‐phase system, whereas anionic detergents such as sodium dodecyl sulfate or sodium deoxycholate were favorable components in the mixed micellar system. The optimum pH value (5.5–5.6) and the optimum Ca²⁺ ion concentration (70 mM) were independent of the reaction system. The head group selectivity in terms of activity toward different phospholipids (PC > phosphatidylethanolamine > phosphatidylglycerol) was similar in both types of reaction systems. Also, the K_M values toward PC were on the same order of magnitude. In contrast, the V_max value in the two‐phase system was 20‐fold lower than in the mixed micellar system. The enzyme was able to catalyze the substitution of choline in PC by ethanolamine, glycerol, and ethylene glycol with high efficiency. l ‐Serine was exchanged for choline with low activity. Myo‐inositol was not an alcohol acceptor, but promoted the hydrolysis of PC.     

How heterogeneous are adolescents’ preferences for natural and semi-natural riverscapes as recreational settings?

Recent research has indicated that the younger generations may be disconnected from nature and even show some dislike for natural conditions. This study addressed adolescents’ preferences for riverscapes with varying fluvial dynamics as recreational settings. A stated choice survey with digitally calibrated river scenarios asked Austrian pupils (N = 281) about their preferences for several physical and social characteristics of a floodplain landscape. Pupils perceived riverscapes with a high water dynamic as best for recreation, while water bodies with low water levels and algae, dry river sites, floods and littered trails were disliked. Heterogeneity among the pupils was found with one smaller segment preferring settings with high water dynamic and low human impact, while the larger one preferred settings with more human impact and low water dynamic. This segment that shows some dislike for natural conditions had less experience with rivers and scored lower on natural river-related attitudes and perceptions. Implications for recreational river planning and aesthetic assessments are derived.     

Highly active screen-printed IrTi4O7 anodes for proton exchange membrane electrolyzers

Electroceramic support materials can help reducing the noble-metal loading of iridium in the membrane electrodes assembly (MEA) of proton exchange membrane (PEM) electrolyzers. Highly active anodes containing Ir-black catalyst and submicronic Ti₄O₇ are manufactured through screen printing technique. Several vehicle solvents, including ethane-1,2-diol; propane-1,2-diol and cyclohexanol are investigated. Suitable functional anodic layer with iridium loading as low as 0.4 mg cm^?2 is obtained. Surface properties of the deposited layers are investigated by atomic force microscopy (AFM). The most homogeneous coating with the highest electronic conductivity is obtained using cyclohexanol. Tests in PEM electrolyzer operating at 1.7 V and 40 °C demonstrate that the CCM with anode coated with cyclohexanol presents a 1.5-fold higher Ir-mass activity than that of the commercial CCM.