Dermaseptin, a peptide antibiotic, stimulates microbicidal activities of polymorphonuclear leukocytes

Dermaseptin (DRs S1), a 34-amino acid residue cationic antimicrobial peptide was studied for its effects on the production of reactive oxygen species (respiratory burst) and exocytosis of polymorphonuclear leukocytes (PMN). Treatment of PMN with DRs S1 (10-100 nM) stimulated significant production of reactive oxygen species (approximately a 2-fold increase relative to control) and release of myeloperoxidase. In addition, low DRs S1 concentrations (1-10 nM) primed the stimulation of respiratory burst induced by zymosan particles. In contrast to the native peptide, a dermaseptin fragment without either the COOH-terminal (DRs 1-10) or NH2 terminal (DRs 16-34) portion was inactive. The DRs S1-induced respiratory burst was inhibited by a selective protein kinase C inhibitor, GF 109203X, and was associated with early signalling events such as a rapid and transient elevation of cytosolic-free calcium concentration and phospholipase D activity. These data provide the first evidence of stimulating and priming properties of a peptide antibiotic on microbicidal activities of neutrophils, suggesting a potential role of dermaseptin in modulating host-defense mechanisms.     

A formal approach to the specification and the behavior validation of real-time systems based on rewriting logic

Design of real time and concurrent systems requires formal approaches in order to facilitate verification and validation at each step. Methods based on formal logic have been previously suggested but they often work only in a specific domain and are generally only possible with specialized users. In an attempt to overcome these two restrictions, this paper proposes a method based on rewriting logic. A grounding in theory is not a prerequisite for users. The method integrates modularity and abstraction and follows the main principles of an object-oriented approach. Different tools are available: a graphical editor for the specification of the structure and the behavior of the objects, an inference engine for rule validation and a generator of prototypes.     

Optimized bioregenerative space diet selection with crew choice

Previous studies on optimization of crew diets have not accounted for choice. A diet selection model with crew choice was developed. Scenario analyses were conducted to assess the feasibility and cost of certain crew preferences, such as preferences for numerous-desserts, high-salt, and high-acceptability foods. For comparison purposes, a no-choice and a random-choice scenario were considered. The model was found to be feasible in terms of food variety and overall costs. The numerous-desserts, high-acceptability, and random-choice scenarios all resulted in feasible solutions costing between 13.2 and 17.3 kg ESM/person-day. Only the high-sodium scenario yielded an infeasible solution. This occurred when the foods highest in salt content were selected for the crew-choice portion of the diet. This infeasibility can be avoided by limiting the total sodium content in the crew-choice portion of the diet. Cost savings were found by reducing food variety in scenarios where the preference bias strongly affected nutritional content.     

Sea Surface Salinity Retrieval for the SMOS Mission Using Neural Networks

During the in-flight phase, using neural networks to retrieve the sea surface salinity from the observed Soil Moisture and Ocean Salinity brightness temperatures (TBs) is an empirical approach that offers the possibility of being independent from any theoretical emissivity model. Due to the large variety of incidence angles, several networks are needed, as well as a preprocessing phase to adapt the observed TBs to the inputs of the networks. When using the first Stokes parameter as an input, the retrieved salinity has a good accuracy (with an error of around 0.6 psu). Furthermore, the solutions for improving these performances are discussed.     

The rheological modelling of carbon nanotube (CNT) suspensions in steady shear flows

This paper is concerned with the rheological modelling of both chemically treated and untreated carbon nanotube (CNT) suspended in a Newtonian epoxy resin. CNT suspensions generally exhibited shear-thinning characteristic—the apparent viscosity decreases as shear rate increases—when subject to steady shear flows. Chemically treated CNT suspensions with little optical microstructure were found to exhibit a less significant shear-thinning effect compared with untreated CNT suspensions where clear optical aggregates were observed. In the case of treated CNT suspensions, the shear-thinning characteristic could be described using a Fokker–Planck based orientation model. The model assumed that the treated CNTs behaved as high aspect ratio rods and that shear flow was able to align the CNTs in the flow direction, thereby resulting in a decrease in the shear viscosity. Despite the success in describing the rheological response of treated CNT in steady shear flows, the orientation model failed to explain the more pronounced shear-thinning effect observed in untreated CNT suspensions having a hierarchy of aggregate structures. A new model called the aggregation/orientation (AO) model was formulated by modifying the Fokker–Planck equation. The AO model considered elements of aggregation as well as CNT orientation and it was capable of capturing the steady shear response of untreated CNT suspensions.     

Food neophobia levels of Lebanese and American college students

Food neophobia, defined as the reluctance to eat novel foods, is a personality trait that influences everyday human food choices. The objectives of this work were first, to compare food neophobia levels among American and Lebanese college students (n = 1122), second to assess the effect of personal variables such as country of residence, socio-economic status (SES) on food neophobia levels, and third to examine the effect of food neophobia levels on the familiarity and willingness to try ratings of familiar and novel foods. Average food neophobia scale (FNS) score for all respondents was 33.1 ± 11.3. Differences on FNS scores were obtained between American (29.8) and Lebanese (36.4) students (P < 0.05). Number of trips taken outside the country, frequency of eating ethnic foods and history of sickness after eating a new food were significant (P < 0.05). Food neophilic subjects had higher familiarity and willingness to try scores for familiar and novel foods.     

Technologies for large scale seawater desalination using concentrated solar radiation

This paper shows the principles and the present state of the art of concentrating solar power technology and explains the option for seawater desalination, either using electricity or steam generated in such plants. The economic potential of this technology in the MENA region can cope with the present and the expected future demand of electricity and water. First projects are now being realized, for electricity and also for combined heat and power for desalination, electricity and cooling.     

Reliability estimations of components from masked system life data

This paper introduces estimations of reliability values for the individual components in a series system using masked system life data. In particular, we compute the maximum likelihood and Bayes estimates of component reliabilities when the system components have constant failure rates. In obtaining Bayes estimates, it is assumed that the component reliabilities are independent random variables having piecewise linear prior distributions. The model is illustrated for a two-component series. A numerical simulation study is presented to show how one can utilize the present approach to compute estimations of component reliabilities for a practical problem. Further, we investigate the comparison between the maximum likelihood and Bayes estimates, based on the respective percentage errors.