An ethnographical study of the accessibility barriers in the everyday interactions of older people with the web

Older people experience many barriers when they access to the web. However, little is known about which barriers limit more (or less) their daily interactions. This paper presents some findings based on an ethnographical study of the everyday interactions of nearly 400 older people with the web over 3 years. Difficulties remembering steps, understanding terms and using the mouse are more severe than problems perceiving visual information, understanding icons and using the keyboard. This is largely explained by inclusion, independence and socialization, which are the three key components of real-life web use. This paper also shows that these aspects should be considered in other areas of web and ICT accessibility, as technophobia is not the only experience in the interactions of older people with the web, and both social relationships and life experiences beyond technologies need to be taken into account apart from age-related changes in abilities. These findings suggest that the current focus on compensating for age-related changes in functional abilities needs to be widened. Working towards making the web more accessible should not be divorced from real-life use. This paper discusses implications for web (and ICT) design, training and support.     

Designing van der Waals Forces between Nanocolloids

van der Waals (VDW) dispersion forces are often calculated between colloidal particles by combining the Dzyaloshinskii-Lifshitz-Pitaevskii (DLP) theory with the Derjaguin approximation; however, several limitations prevent using this method for nanocolloids. Here we use the Axilrod-Teller-Muto 3-body formulation to predict VDW forces between spherical, cubic, and core-shell nanoparticles in a vacuum. Results suggest heuristics for "designing" nanocolloids to have improved stability.     

Extrusion conditions and zea mays endosperm hardness affecting gluten‐free spaghetti quality

The effects of extrusion temperature (80, 90 and 100 °C) and flour moisture content (27%, 31% and 35%) on corn spaghetti quality were evaluated according to a factorial experimental design. Flours obtained from a soft and hard endosperm were processed in a Brabender single screw extruder. Corn spaghettis with good cooking characteristics and resistance to overcooking were obtained by extrusion at 27% flour moisture content for the three temperatures used. They have higher resistance to hydration, long cooking time (around 11 vs. 7 min for poor quality) and low cooking loss (lower than 9% for a 10‐min overcooking). Softer endosperm allowed obtaining better spaghetti quality. Among different physicochemical properties, enzyme susceptibility could be used as an indicator of mechanical energy dissipated by friction. During extrusion cooking, the native structure is partially destroyed, and new crystalline ones, corresponding to the amylose–lipid complex, are formed.     

Acetylcholinesterase‐inhibitor hydrolysates obtained from ‘in vitro’ enzymatic hydrolysis of mannoproteins extracted from different strains of yeasts

In vitro inhibitory activity against acetylcholinesterase (AChE) of peptides obtained by enzymatic hydrolysis of mannoproteins extracted from strains of yeasts was investigated. Yeast mannoproteins were extracted from strains belonging to the genera Brettanomyces, Candida, Pichia and Saccharomyces isolated from dairy products. They were obtained by heat treatment in citrate buffer and purified by affinity chromatography with concanavalin A. Each purified extract was subsequently hydrolysed with proteolytic enzymes (trypsin, pepsin, chymotrypsin and proteinase K) applied individually or in combination, thus generating smaller peptides. Inhibitory activity of the latter against AChE was determined. The molecular weight of mannoproteins, determined by SDS‐PAGE, was between 6.5 and 30 kDa. As regards AChE inhibition, a preliminary screening of all hydrolysed extracts was performed, yielding variable results with 59% maximum inhibition. Subsequently, when inhibitory concentration 50 (IC50) was determined, the extracts showed higher inhibitory activity (between 6.75 and 12.3 mg mL^?1). Results showed that the mannoproteins separated from yeast strains of food origin generated bioactive peptides by enzymatic hydrolysis, which can be of interest to the manufacturing of food with potential functional properties.     

Gas Adsorption in Novel Environments, Including Effects of Pore Relaxation

Adsorption experiments have been interpreted frequently with simplified model geometries, such as ideally flat surfaces and slit or cylindrical pores. Recent explorations of unusual environments, such as fullerenes and metal-organic-framework materials, have led to a broadened scope of experimental, theoretical and simulation investigations. This paper reviews a number of such studies undertaken by our group. Among the topics receiving emphasis are these: universality of gas uptake in pores, relaxation of a porous absorbent due to gas uptake, and the novel phases of gases on a single nanotube, all of which studies have been motivated by recent experiments.     

Effect of Gastric Digestion pH on Iron, Zinc, and Calcium Dialyzability from Preterm and Term Starting Infant Formulas

ABSTRACT: Iron, zinc, and calcium dialyzability from preterm and term starting infant formulas were determined after in vitro digestion, using special gastric conditions prevailing in preterm and newborn infants. Mineral dialyzability was studied using pH 2.0,3.5, and 4.5 for gastric digestion. The effect of gastric pH was more important on iron dialyzability (FeD) and zinc dialyzability (ZnD) than on calcium dialyzability (CaD). The effect on iron dialyzability was remarkable in fluid formulations with high digestibility: FeD was 18% to 20% when gastric digestion was made at pH 2, decreasing to 3% when made at pH 4.5. In most powder infant formulas with the lowest digestibility, FeD remained close to 10% despite variations in gastric digestion pH. Percent zinc dialyzability (ZnD%) steadily decreased when gastric digestion pH increased. At each pH, percent iron dialyzability (FeD%) and ZnD% from human milk were higher than those from infant formulas. Evaluation of mineral dialyzability from these infant formulas, using a gastric digestion pH prevailing in preterm and newborn infants, can provide valuable information on mineral availability.     

Use of a multivariate approach to assess the incidence of Alicyclobacillus spp. in concentrate fruit juices marketed in Argentina: results of a 14-year survey

The purpose of this study was to determine the incidence of Alicyclobacillus spp. in fruit/vegetable juices (concentrated pulps and clarified and non-clarified juices) marketed in Argentina between 1996 and 2009.The presence of Alicyclobacillus was determined in a total of 8556 samples of fruit and vegetable juices (apple, pear, grape, peach, blend of juices, tangerine, pineapple, orange, mango, plum, guava, apricot, lemon, banana, kiwi, carrot, strawberry, grapefruit, and beetroot) collected in seven Argentinean provinces. Multiple factor analysis (MFA) was carried out on a data matrix that contained the percentage of positive samples, type of juice, raw material and production year.Except for kiwi and orange, Alicyclobacillus was found in juices from all the evaluated raw materials. The highest percentage of positive samples was found for beetroot, strawberry, banana, peach, mango, carrot and plum juices. The percentage of positive samples for these juices ranged from 100% to 24%.Furthermore, the application of multivariate techniques provided an insight on the relationship between the incidence of Alicyclobacillus and production variables. This approach enabled the identification of the most relevant variables that increased the percentage of positive samples among the juices, which could help in developing strategies to avoid the incidence of this bacterium.By means of hierarchical cluster analysis seven groups (clusters) of juices which showed different percentages of positive samples for Alicyclobacillus spp. were identified. This analysis showed that pineapple, peach, strawberry, mango and beetroot juices had higher rates of positivity for Alicyclobacillus than the rest of the evaluated juices. MFA analysis also showed that some clear relationships could be highlighted between the percentage of samples positive for Alicyclobacillus and five types of fruit juices (strawberry, beetroot, grapefruit, pineapple and mango). It was observed that a large proportion of juices produced in 2000, 2005 and 2008 were located in clusters with higher incidence of Alicyclobacillus spp., whereas a larger proportion of clarified concentrate juice and concentrate pulp samples showed higher probability of incidence of Alicyclobacillus in these products. Data presented in this study brings a contribution to the ecology of Alicyclobacillus in fruit/vegetable juices marketed in Argentina. This information would be useful to enhance the microbiological stability of fruit juices regarding the presence of Alicyclobacillus spp.