Influence of encapsulation of emulsified lipids with chitosan on their in vivo digestibility

The influence of interfacial composition on the in vivo digestibility of emulsified and encapsulated lipids was investigated. An electrostatic layer-by-layer deposition technique was used to prepare soybean oil-in-water emulsions that contained lipid droplets coated by lecithin or by lecithin–chitosan. Thirty six 4-week-old male mice were divided into four groups and fed treatment diets for 4 weeks; atherogenic diets supplemented with (A) non-emulsified fat, without chitosan (control), (B) non-emulsified fat, with chitosan, (C) emulsified fat, without chitosan, or (D) emulsified fat encapsulated by chitosan. There were no differences in body weights, food intake, major organ weights, or fecal fat contents between all treatment groups, where total fat absorption was >90%. The results suggest that encapsulation of lipids by chitosan does not inhibit their in vivo digestibility, even though previous studies indicate that chitosan does inhibit their in vitro digestibility. Consequently, it should be possible to use chitosan to microencapsulate lipids and lipid-soluble components without compromising their bioavailability, although further human studies are needed to confirm this.     

Using predictors to partition menu selection times

Selection times of drop-down menus are in many ways influenced by cognitive and motor processes of the user and by design variables of the menu. Since the number of these variables is too large, the contribution of individual variables to selection time cannot be assessed by using factorial designs. Multiple regression is introduced to solve this problem. The technique uses selection times as criterions and a set of general menu characteristics as predictors. The non-standardized slopes β report the increase ( or decrease) in selection time which can be assessed for each predictor. In a first experiment, the validity of the technique was demonstrated replicating various well-known effects in a mouse-driven editor. For example, the selection times increased with the number of subordinate menu items or atypical items. Further, due to motor components of the mouse movement, selection times depended on the spatial position of an item within the menu. In a second experiment, mouse selection was replaced by key selection to stress cognitive processes contributing to response times. The technique yielded results that were sensitive to this variation. Limitations of the technique are discussed.     

Coping With Deficits and Losses in Later Life: From Compensatory Action to Accommodation.

Processes of coping with performance deficits in different domains of functioning were investigated in a 4-year longitudinal study involving a core sample of 762 participants (initial age range: 58-81 years). Compensatory efforts to counteract functional impairments were found to increase up to the age of 70 years. Above that age, a decrease in compensatory efforts was observed that was linked to a decrease in the availability and efficiency of action resources. Contentment with actual performance levels remained stable across the entire age range of the study. Stability of self-evaluations was found to depend on adjustment of personal standards: Scarce action resources were accompanied by a lowering of personal comparison standards and by a downgrading of the importance of the respective domains. Accepting more lenient standards of comparison was found to buffer negative effects of performance deficits on contentment with performance among the older participants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Green hydropower: a new assessment procedure for river management

Hydropower is the most important renewable electricity source worldwide. It shows clear advantages for the global CO₂ balance but creates serious ecological impacts on a local scale. As a consequence, concern for the conservation of natural river ecosystems is growing within society and more people are willing to pay extra for so‐called ‘green electricity’. The definition of ‘green’, however, is not straightforward and customers cannot directly examine the quality of electricity products. Therefore, credible certification of high ecological standards is essential for successful green electricity marketing. In this paper we introduce a new assessment procedure for evaluating environmentally compatible hydropower production. This so‐called ‘Green Hydro’ concept was developed in the context of a multidisciplinary case study on a 400 MW hydropower scheme in the Southern Alps of Switzerland. The concept guarantees both general standards for different schemes operating in different types of watersheds and flexibility for local particularities. We developed an environmental management matrix that considers basic criteria and eco‐investments and covers five environmental areas of concern (i.e. hydrological character, connectivity, morphology, landscape, and biological communities). The ecological perspective is complemented by five management domains (i.e. instream flow regimes, hydropeaking, reservoir and bedload management, and power plant structures). Applying assessment and modelling tools for the Green Hydro procedure showed that dynamic habitat models allowed quantification of the effects of different instream flow regulations at morphologically distinct sites. In this case, morphological restoration could be more beneficial than increasing the minimum flow. The first experience with the Green Hydro certification is encouraging. So far, 13 facilities have successfully passed the certification procedure. They produce a total of 186 GWh green electricity per year, which is sufficient for the supply of almost 40 000 households in Switzerland. Copyright © 2004 John Wiley & Sons, Ltd.     

Isomeric diacylglycerols – Determination of 1,2‐ and 1,3‐diacylglycerols in virgin olive oil

The “Joint Committee for the Analysis of Fats, Oils, Fatty Products, Related Products and Raw Materials (GA Fett)” has developed the following method for the determination of isomeric diacylglycerols in virgin olive oils to detect the freshness of oils. It is intended to include this method in Section C, Chapter VI of the German Standard Methods.*     

Towards Automatic Creation of Realistic Anthropomorphic Models for Realtime 3D Telecommunication

This contribution describes the creation of highly realistic 3D models of participants for distributed 3D videoconferencing systems. These models consist of a flexible triangular mesh surrounding an interior skeleton structure, which is based on a simplified human skeleton. The vertices of the predefined mesh template are arranged in rigid rings along the bones of the skeleton. Using 3D data obtained by a stereoscopic approach the size and shape of this initial mesh is adapted to the real person. Adaptation allows to texture the model from real images leading to a natural impression. The mesh organization in rigid rings gives an efficient way for surface deformation according to the skeleton movements. The resulting model is transmitted once and subsequently animated using the simple parameter set of the interior skeleton structure.     

Using 15N‐Ammonium to Characterise and Map Potassium Binding Sites in Proteins by NMR Spectroscopy

A variety of enzymes are activated by the binding of potassium ions. The potassium binding sites of these enzymes are very specific, but ammonium ions can often replace potassium ions in vitro because of their similar ionic radii. In these cases, ammonium can be used as a proxy for potassium to characterise potassium binding sites in enzymes: the ¹H,¹⁵N spin‐pair of enzyme‐bound ¹⁵NH₄⁺ can be probed by ¹⁵N‐edited heteronuclear NMR experiments. Here, we demonstrate the use of NMR spectroscopy to characterise binding of ammonium ions to two different enzymes: human histone deacetylase 8 (HDAC8), which is activated allosterically by potassium, and the bacterial Hsp70 homologue DnaK, for which potassium is an integral part of the active site. Ammonium activates both enzymes in a similar way to potassium, thus supporting this non‐invasive approach. Furthermore, we present an approach to map the observed binding site onto the structure of HDAC8. Our method for mapping the binding site is general and does not require chemical shift assignment of the enzyme resonances.     

Floc volume effects in suspensions and its relevance for wastewater engineering

The aim of this paper is to better understand oxygen transfer reduction caused by floc suspensions. We demonstrate that the overall floc volume significantly influences oxygen transfer depletion. Submerged fine bubble and coarse bubble diffusers are affected in the same way by this phenomenon. The mixed liquor suspended solids concentration (MLSS concentration) is not an appropriate parameter for describing or relating phenomena that are caused by the overall floc volume in activated sludge (e.g., oxygen transfer depression and sludge sedimentation characteristics). A better correlation is achieved by using the mixed liquor volatile suspended solids concentration (MLVSS concentration). To characterize the effects of the overall floc volume in suspensions whose MLVSS concentration cannot be determined (e.g., inorganic iron hydroxide flocs), a new method-the hydrostatic floc volume (HFV)-that approximates the overall floc volume in floc suspensions is introduced. Application of this method demonstrates that oxygen transfer depression caused by iron hydroxide flocs and activated sludge flocs is similar.     

Triggering the volume phase transition of core-shell Au nanorod-microgel nanocomposites with light

We have coated gold nanorods (NRs) with thermoresponsive microgel shells based on poly(N-isopropylacrylamide) (pNIPAM). We demonstrate by simultaneous laser-heating and optical extinction measurements that the Au NR cores can be simultaneously used as fast optothermal manipulators (switchers) and sensitive optical reporters of the microgel state in a fully externally controlled and reversible manner. We support our results with optical modeling based on the boundary element method and 3D numerical analysis on the temperature distribution. Briefly, we show that due to the sharp increase in refractive index resulting from the optothermally triggered microgel collapse, the longitudinal plasmon band of the coated Au NRs is significantly red-shifted. The optothermal control over the pNIPAM shell, and thereby over the optical response of the nanocomposite, is fully reversible and can be simply controlled by switching on and off a NIR heating laser. In contrast to bulk solution heating, we demonstrate that light-triggering does not compromise colloidal stability, which is of primary importance for the ultimate utilization of these types of nanocomposites as remotely controlled optomechanical actuators, for applications spanning from drug delivery to photonic crystals and nanoscale motion.