αα'-trehalose 6,6'-dibehenate in non-phospholipid-based liposomes enables direct interaction with trehalose, offering stability during freeze-drying

Trehalose is a well known protector of biostructures like liposomes and proteins during freeze-drying, but still today there is a big debate regarding its mechanism of action. In previous experiments we have shown that trehalose is able to protect a non-phospholipid-based liposomal adjuvant (designated CAF01) composed of the cationic dimethyldioctadecylammonium (DDA) and trehalose 6,6-dibehenate (TDB) during freeze-drying [D. Christensen, C. Foged, I. Rosenkrands, H.M. Nielsen, P. Andersen, E.M. Agger, Trehalose preserves DDA/TDB liposomes and their adjuvant effect during freeze-drying, Biochim. Biophys. Acta, Biomembr. 1768 (2007) 2120-2129]. Furthermore it was seen that TDB is required for the stabilizing effect of trehalose. Herein, we show using the Langmuir-Blodgett technique that a high concentration of TDB present at the water-lipid interface results in a surface pressure around 67 mN/m as compared to that of pure DDA which is approximately 47 mN/m in the compressed state. This indicates that the attractive forces between the trehalose head group of TDB and water are greater than those between the quaternary ammonium head group of DDA and water. Furthermore, addition of trehalose to a DDA monolayer containing small amounts of TDB also increases the surface pressure, which is not observed in the absence of TDB. This suggests that even small amounts of trehalose groups on TDB present at the water-lipid interface associate free trehalose to the liposome surface, presumably by hydrogen bonding between the trehalose head groups of TDB and the free trehalose molecules. Hence, for CAF01 the TDB component not only stabilizes the cationic liposomes and enhances the immune response but also facilitates the cryo-/lyoprotection by trehalose through direct interaction with the head group of TDB. Furthermore the results indicate that direct interaction with liposome surfaces is necessary for trehalose to enable protection during freeze-drying.

Attainment of competitive advantage by the exporter-importer dyad:the role of export offering and import objectives

Although experience shows that the exporter and importer jointly contribute towards the attainment of competitive advantage, past studies have separately examined export-related characteristics or import barriers. This article identifies a subset of critical factors that illustrate how the exporter–importer (E-I) dyad creates and maintains competitive advantage. Based on a sample of Greek importers, a path analytic model was developed that empirically demonstrates that product technology sophistication (PTS), product and service quality and importer strategic objectives are important for the attainment of competitive advantage while price competitiveness and trust upon the exporter are not.

Discriminating behaviors through value added premium online grocery offering

Despite many interest in e-grocery, little has changed, over the years, in the offering that is often geared only towards low value staple products. Yet, from an e-supermarket perspective, the number of sourcing stores is increasing regularly providing an illusion of service improvement. This situation, we argue is leading e-grocery providers to forego profits as consumers need to look both at the competition online and offline to satisfy their overall regular grocery needs. Expansion of e-grocery operations could be better achieved, we argue, by serving diverse and premium priced products (e.g. organic, limited production, regional items; special occasions items and products related to health e.g. allergies, diabetes) and utilizing more efficiently modern logistic techniques. A framework is offered presenting a model including the delivery of premium products from various suppliers and providing an integrated service solution to e-grocery customers that complete traditional supermarket ranges, creating potential high value added products niches. In this context, the objective was to understand the consumer discrimination factors (ie: range of product, delivery timing, location, service quality) leading to intentions towards purchasing more items from e-grocery retailers. Data are derived from a survey of 356 respondents in Turkey’s three biggest metropolitan areas. The relationship between consumer attitudes and demographic characteristics are also analyzed. Factor and SEM analyses are used to discriminate within the sample (n=356, no of items=150). Results, future research and policy implications are discussed.

Investigating offering of vegetables by caregivers of preschool age children

BACKGROUND: Research into the methods which caregivers use to encourage children to eat vegetables is limited, with minimal evidence about what the barriers are to offering these foods. Vegetable consumption in children is typically low, and so gaining information on these factors is vital in order to develop further caregiver-centred interventions to increase children's vegetable consumption. This study aimed to investigate the methods caregivers use to offer vegetables to preschool aged children, as well as the factors which influence whether and how caregivers present vegetables to their children. METHOD: Seventeen caregivers with a preschool aged child participated in focus groups to assess these questions. RESULTS: Thematic analysis indicated that caregivers use a range of methods to offer their children vegetables, with these methods falling into three broad categories: behavioural/active methods, passive methods and food manipulations. Influences on caregiver offering which emerged from the focus groups formed four categories: information, cost, parent factors and child factors. CONCLUSIONS: Together with large-scale quantitative data, this information can be used to shape future interventions aiming to increase children's vegetable intake as well as to tailor advice given to caregivers striving to achieve a healthful diet for their children.