Dose- and wavelength-dependent oxidation of crystallins by UV light--selective recognition and degradation by the 20S proteasome

The lens of the human eye is a suitable model for age-related alterations at the molecular level. Age-related cataract formation is closely related to the accumulation of oxidatively altered proteins. In this study the influence of UV-A, UV-B, and UV-C irradiation on the proteolytic susceptibility of alpha-, betaL-, and betaH-crystallins by the isolated 20S proteasome was investigated. The proteins were irradiated with 280, 300, and 350 nm monochromatic light. Changes of the physical properties of the crystallins were characterized by absorbance measurements at 280 nm, fluorescence spectra, and SDS-PAGE-electrophoresis. The proteolytic susceptibility of crystallins was maximal after irradiation at 280 nm and three- to fivefold lower at 300 nm. Irradiation at 350 nm was not able to initiate proteolysis, probably due to protein-aggregate formation of higher molecular weight, as shown by SDS-PAGE. The damage of crystallins by UV-C light might be a signal for its proteolytic degradation by the 20S proteasome, whereas UV-B and UV-A do not increase the proteolytic susceptibility to the same extent but promote the formation of crosslinked proteins. Therefore, irradiation with UV, which is not followed by an increase in the proteolytic susceptibility, is accompanied by the formation of crosslinked proteins. It was concluded, that also long UV-B and UV-A may be involved in age-related alterations of the human lens and cataract formation.     

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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TiO2 anatase nanoparticle networks: synthesis, structure, and electrochemical performance

Nanocrystalline anatase TiO(2) materials with different specific surface areas and pore size distributions are prepared via sol-gel and miniemulsion routes in the presence of surfactants. The samples are characterized by X-ray diffraction, nitrogen sorption, transmission electron microscopy, and electrochemical measurements. The materials show a pure anatase phase with average crystallite size of about 10 nm. The nitrogen sorption analysis reveals specific surface areas ranging from 25 to 150 m(2) g(-1) . It is demonstrated that the electrochemical performance of this material strongly depends on morphology. The mesoporous TiO(2) samples exhibit excellent high rate capabilities and good cycling stability.     

Bioaccumulation of cyanuric acid in edible tissues of shrimp following experimental feeding

Due to concerns that cyanuric acid (CYA)-contaminated feed had been used in aquaculture and could enter the human food chain, a method to quantify CYA residues in the edible tissues of fish and shrimp was previously developed and validated. This paper provides further data on the deliberate feeding of CYA to shrimp to determine the extent of residue accumulation in edible tissue. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for the analysis of CYA in shrimp tissue. Edible tissue of shrimp fed 1666 or 3333 mg kg?1 CYA in their diet (approximately 55 and 124 mg kg?1 body weight) contained 0.767 and 0.406 mg kg?1 CYA, respectively. The residue levels are below the World Health Organization (WHO) tolerable daily intake level for CYA and are generally considered unlikely to pose a human health risk.     

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.     

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.     

Degrees of engagement in interactive workspaces

This paper presents a new perspective of the impact of collaboration technology on the degrees of engagement and specific interaction zones in interactive workspaces. The study is at the intersection of the design of physical work spaces, i.e., bricks, rich electronic content such as video, audio, sketching, CAD, i.e., bits, and new ways people behave in communicative events, i.e., interaction. The study presents: (1) an innovative multi-modal collaboration technology, called RECALL (patented by Stanford University), that supports the seamless, real-time capture of concept generation during project brainstorming and project review sessions, (2) the deployment of RECALL in an interactive workspace that supports real project review sessions, called FISHBOWL, and (3) the observations of the impact of RECALL and the interactive workspace on degrees of engagement and interaction zones as it is deployed in the specific FISHBOWL sessions.     

Does Class Size in First Grade Relate to Children's Academic and Social Performance or Observed Classroom Processes?

This study evaluated the extent to which first-grade class size predicted child outcomes and observed classroom processes for 651 children (in separate classrooms). Analyses examined observed child-adult ratios and teacher-reported class sizes. Smaller classrooms showed higher quality instructional and emotional support, although children were somewhat less likely to be engaged. Teachers in smaller classes rated typical children in those classes as more socially skilled and as showing less externalizing behavior and reported more closeness toward them. Children in smaller classes performed better on literacy skills. Larger classrooms showed more group activities directed by the teacher, teachers and children interacted more often, and children were more often engaged. Lower class sizes were not of more benefit (or harm) as a function of the child's family income. First-grade class size in the range typical of present-day classrooms in the United States predicts classroom social and instructional processes as well as relative changes in social and literacy outcomes from kindergarten to first grade. (PsycINFO Database Record (c) 2010 APA, all rights reserved)