Constant round group key agreement protocols: A comparative study

The scope of this paper is to review and evaluate all constant round Group Key Agreement (GKA) protocols proposed so far in the literature. We have gathered all GKA protocols that require 1,2,3,4 and 5 rounds and examined their efficiency. In particular, we calculated each protocol’s computation and communication complexity and using proper assessments we compared their total energy cost. The evaluation of all protocols, interesting on its own, can also serve as a reference point for future works and contribute to the establishment of new, more efficient constant round protocols.     

Migration of bisphenol A from polycarbonate baby bottles under real use conditions

Migration of the potential endocrine disrupter, bisphenol A (BPA), from 31 polycarbonate (PC) baby bottles into aqueous food simulants was studied under real repetitive use, using a sensitive and fully validated liquid chromatographic method with fluorescence detection. Confirmation of the presence of BPA was performed by liquid chromatography–mass spectrometry (LC–MS). The effects of cleaning in a dishwasher or with a brush, sterilization with boiling water and the temperature of migration were examined. It was shown that temperature was the crucial factor for the migration of BPA from the plastic bottles to water. All samples released BPA in the concentration range 2.4–14.3 µg kg^?1 when filled with boiled water and left at ambient temperature for 45 min. The decrease of BPA release in the sterilization water and in the food simulant over 12 cycles of use indicated that the hypothesis of polymer degradation in water is dubious. Estimated infantile dietary exposure, regarding the use of PC baby bottles, ranged between 0.2 and 2.2 µg kg^?1 bw day^?1, which is below the Tolerable Daily Intake of 50 µg kg^?1 bw recently established by EFSA.     

Study of emulsions and foams stabilized with Phaseolus vulgaris or Phaseolus coccineus with the addition of xanthan gum or NaCl

The properties of oil/water emulsions stabilized with 1% w/v common bean (Phaseolus vulgaris L.) or scarlet runner bean (P. coccineus L.) proteins, extracted by isoelectric precipitation or ultrafiltration, at pH 7.0 and 5.5 were studied. The stability of emulsions, evaluated on the basis of droplet size, creaming, viscosity and protein adsorption measurements, is increased by the addition of xanthan (0.1 and 0.25% w/v). This is probably due to the increase in the continuous phase viscosity and the creation of a network, which prevents the oil droplets from coalescing. Also, the ability and stability of 1 or 2% w/v foams was studied. Xanthan (0.25% w/v) does not enhance foam formation, but promotes foam stability, possibly owing to the increased viscosity of the aqueous phase, making it more difficult for air to enter the system and create a satisfactory foam volume. The addition of NaCl destabilizes emulsions by lowering the energy barrier and therefore increasing the tendency of the oil droplets to aggregate. However, NaCl at a certain concentration seems to promote the emulsion stability and foaming ability and foam stability. This could be attributed to the alteration of the protein molecule configuration leading to the building of a rigid and viscoelastic protein film around the droplet. Copyright © 2006 Society of Chemical Industry     

intGuide: A platform for context-aware services featuring augmented-reality, based on the outcome of European Research Projects

As people become increasingly acquainted with information technology, they demand continuous availability of services related to their work or leisure. The era of ubiquitous computing announced long ago is currently turning into an everyday reality at an ever-increasing pace. Alongside the evolution of ubiquitous and nomadic computing, the need of people to access vast amounts of information in a comprehensive and efficient way gives rise to the areas of information visualization and augmented-reality. Such technologies allow for the comprehensive presentation of visual information equally addressing the needs of different categories of people.

In the past 5 years, we have been active in a set of European Research Projects addressing the above-mentioned research directions, with the long-term goal to develop a software platform that will enable context-aware services deploying advanced visualization technology in a series of application domains, such as cultural heritage dissemination, interactive television and retail industry. The multitude of the application domains addressed, as well as the multidisciplinary expertise necessary to create a generic platform was successfully addressed in complementary research activities. In this paper, we present the idea of a platform for context-aware services by exploiting advanced visualization technology and subsequently we briefly review the research projects that delivered valuable pieces in the overall puzzle. Emphasis is put on the practical issues of the implementation and deployment in different application scenarios.     

Textural properties of legume protein isolate and polysaccharide gels

The influence of legume proteins from lupin, pea and fababean on the formation of gels prepared by heat treatment in the absence or presence of xanthan gum, locust bean gum and NaCl was investigated. The resulting fracture and texture properties of gels not only are associated with the heating process used to form the gel but also depend on the conformational aspects of xanthan–locust bean gum in admixture with legume proteins, which after 10 days of aging reinforce the system. The fracture and textural properties are explained in terms of the effect of the protein–polysaccharide molecular structure and physicochemical conditions applied in the gel system during the gel preparation and measurements. Copyright © 2006 Society of Chemical Industry     

Effect of durum flour enrichment with chickpea flour on the characteristics of dough and lasagne

The ability of chickpea flour to enrich pasta products (e.g. lasagne) was studied. In addition, the influence of protein and other components upon the rheological properties of the dough and the cooking quality of the wheat–chickpea blends was determined. Supplementing lasagne with 5–20% w/w chickpea flour improves the physical characteristics of dough, which achieves optimum strength and extensible properties thus allowing the lasagne to maintain a firm and elastic form. Organoleptic properties (colour, flavour and overall acceptability) improved with a low proportion of chickpea flour, especially for 5% w/w substitution. For supplementation ≥ 30%, while the content of the total protein increased along with the level of fortification, lasagne processing, handling and cooking characteristics deteriorated proportionally. This could be attributed primarily to the gluten fraction, which decreases upon being diluted by the added chickpea protein. The rheological properties of high supplemented dough products (30–50% w/w) have low extensograph values and the lasagne obtained has a brown colour and a soft mushy taste that is unacceptable to consumers. So, durum wheat flour can carry 5–10% (w/w) of chickpea flour and still meet the specification of pasta products in terms of firmness, cooking quality and sensory evaluation. Copyright © 2006 Society of Chemical Industry     

Surface tension of Phaseolus vulgaris and coccineus proteins and effect of polysaccharides on their foaming properties

The surface tension of protein isolates from common bean (Phaseolus vulgaris L.) and scarlet runner bean (Phaseolus coccineus L.), prepared by isoelectric precipitation and ultrafiltration was evaluated, with respect to protein concentration (0.001–0.1% w/v) and pH (pH 4.5, 5.5, 7.0 and 8.0). Surface tension was most reduced, and with a higher rate of reduction at higher protein concentration and at pH 8.0. Foams (1, 2% w/v protein), at the same pH values, with and without the addition of polysaccharides, were studied. The proteins’ foaming behaviour was related to their adsorption behaviour. Arabic gum, locust bean gum (0.1% and 0.25% w/v), xanthan gum and a xanthan/locust bean gum mixture (0.1% w/v) had a positive effect on foam creation. All polysaccharides increased foam stability, probably due to the viscosity increase and to the creation of a network, which prevents the air droplets from coalescence. Isolates from P. coccineus and isolates obtained by ultrafiltration seemed to exhibit better foaming properties.     

The occurrence of priority PAHs, nonylphenol and octylphenol in inland and coastal waters of Central Greece and the Island of Lesvos

Polycyclic aromatic hydrocarbons (PAHs) as well as nonylphenol (NP) and octylphenol (OP) are substances of major environmental concern because of their adverse health effects on organisms, including endocrine disrupting activity. Seven PAHs, NP and OP have been included in the priority list of substances regulated by 2000/60/EC Water Framework Directive. The present work concerns the investigation of the occurrence of the seven priority PAHs, NP and OP in surface and coastal waters in Central Greece and the Island of Lesvos. Samples were collected and analyzed seasonally for one year from the four reservoirs that supply water to Athens: Mornos, Marathonas, Yliki and Evinos. Samples were also collected from inland waters of the Lesvos Island (the rivers Mylopotamos and Evergetoulas), and from coastal waters (five sampling points) of the Mytilene area, which is the capital city of the Island of Lesvos. The results have shown that in most cases the water samples that were analyzed are free from PAHs, possibly because of lack of PAHs release sources nearby the particular areas, or due to the adsorption of PAHs on sediments. NP occurred at low levels in several cases, while OP was detected only in one sample.     

Late‐onset Pompe's disease in a hemodialysis patient: A first case report

A 37‐year‐old hemodialysis patient appeared with unusual somnolence during 2 successive hemodialysis sessions. Blood gas analysis revealed hypercapnic respiratory failure and spirometry restrictive lung disease. After exclusion of other causes of restrictive lung disease with chest CT‐scan and cerebrum MRI, electrophysiological study revealed myopathy. Because besides lordosis and limb‐girdle gait the patient was ambulant the possibility of late‐onset Pompe's disease was set and confirmed with evaluation of α‐glucosidase activity and genetic analysis. Enzyme replacement therapy (ERT) with aglucosidase alfa was started. Due to inaccessibility of veins in the arm without the arteriovenous fistula, during the last 1 year, the patient received the ERT through the venous line of the hemodialysis circuit. Three years later the patient remains ambulant without the need of any assistant device and preserved his pulmonary function. This is the first described case of late‐onset Pompe's disease in a hemodialysis patient treated with ERT.