SELFNET 5G mobile edge computing infrastructure: Design and prototyping

This paper presents the design and prototype implementation of the SELFNET fifth-generation (5G) mobile edge infrastructure. In line with the current and emerging 5G architectural principles, visions, and standards, the proposed infrastructure is established primarily based on a mobile edge computing paradigm. It leverages cloud computing, software-defined networking, and network function virtualization as core enabling technologies. Several technical solutions and options have been analyzed. As a result, a novel portable 5G infrastructure testbed has been prototyped to enable the preliminary testing of the integrated key technologies and to provide a realistic execution platform for further investigating and evaluating software-defined networking– and network function virtualization–based application scenarios in 5G networks.     

Global memory schemes for dynamic optimization

Nowadays, it is common to find research problems (in system biology, mobile applications, etc.) that change over time, requiring algorithms which dynamically adapt the search to the new conditions. In most of them, the utilization of some information from the past allows to quickly adapt after a change. This is the idea underlining the use of memory in this field, what involves key design issues concerning the memory content, the process of update, and the process of retrieval. In this article, we focus on global memory schemes, which are the most intuitive and popular ones, and perform an integral analysis of current design variants based on a comprehensive set of benchmarks. Results show the benefits and drawbacks of each strategy, as well as the effect of the algorithm and problem features in the memory performance.     

Modified ferrous oxidation‐xylenol orange method to determine lipid hydroperoxides in fried snacks

A modified ferrous oxidation‐xylenol orange (FOX) method was adapted to measure lipid hydroperoxides (LHP) in lipid extracts from snack foods fried in vegetable oils. First, a methanol‐based FOX reaction medium was assayed, but this became turbid upon addition of the lipid extracts dissolved in ethanol. To avoid the precipitation of lipids, the polarity of the reaction medium was reduced by lowering its water content and by replacing the methanol as the basis of the medium for less polar solvents. Some of the solvents used instead of methanol yielded a lower FOX reaction response. Of the reaction media assayed, the one based on dichloromethane/ethanol (3:2, vol/vol) was not turbid at high lipid extract concentrations (assayed at up to 25 mg of lipid extract/mL reaction medium) and provided the same response level as the methanol‐based medium. Thus, this FOX method shows high sensitivity and is particularly useful for lipid extracts with low LHP content. This method was also successfully applied to edible oils. Solvents such as 2‐propanol, ethyl acetate and butanol were discarded, because they easily produce hydroperoxides, which interfere in the FOX reaction. Xylenol orange preparations from a number of suppliers were tested, and some differences affecting the sensitivity of the reaction were observed.     

A bi-population based scheme for an explicit exploration/exploitation trade-off in dynamic environments

Optimisation in changing environments is a challenging research topic since many real-world problems are inherently dynamic. Inspired by the natural evolution process, evolutionary algorithms (EAs) are among the most successful and promising approaches that have addressed dynamic optimisation problems. However, managing the exploration/exploitation trade-off in EAs is still a prevalent issue, and this is due to the difficulties associated with the control and measurement of such a behaviour. The proposal of this paper is to achieve a balance between exploration and exploitation in an explicit manner. The idea is to use two equally sized populations: the first one performs exploration while the second one is responsible for exploitation. These tasks are alternated from one generation to the next one in a regular pattern, so as to obtain a balanced search engine. Besides, we reinforce the ability of our algorithm to quickly adapt after cnhanges by means of a memory of past solutions. Such a combination aims to restrain the premature convergence, to broaden the search area, and to speed up the optimisation. We show through computational experiments, and based on a series of dynamic problems and many performance measures, that our approach improves the performance of EAs and outperforms competing algorithms.     

Fate of Triclocarban,Triclosan and Methyltriclosan during wastewater and biosolids treatment processes

Triclocarban (TCC) and Triclosan (TCS) are two antibacterial chemicals present in household and personal care products. Methyltriclosan is a biodegradation product of TCS formed under aerobic conditions. TCC and TCS are discharged to Waste Water Treatment Plants (WWTP) where they are removed from the liquid phase mainly by concentrating in the solids. This study presents a thorough investigation of TCC, TCS and MeTCS concentrations in the liquid phase (dissolved + particulate) as well as solid phases within a single, large WWTP in the U.S. Total TCC and TCS concentrations decreased by >97% with about 79% of TCC and 64% of TCS transferred to the solids. The highest TCC and TCS removal rates from the liquid phase were reached in the primary treatment mainly though sorption and settling of solids. The TCC mass balances showed that TCC levels remain unchanged through the secondary treatment (activated sludge process) and about an 18% decrease was observed through the nitrification–denitrification process. On the other hand, TCS levels decreased in both processes (secondary and nitrification–denitrification) by 10.4 and 22.6%, respectively. The decrease in TCS levels associated with observed increased levels of MeTCS in secondary and nitrification–denitrification processes providing evidence of TCS biotransformation. Dissolved-phase concentrations of TCC and TCS remained constant during filtration and disinfection. TCC and TCS highest sludge concentrations were analyzed in the primary sludge (13.1 ± 0.9 μg g^?1 dry wt. for TCC and 20.3 ± 0.9 μg g^?1 dry wt. for TCS) but for MeTCS the highest concentrations were analyzed in the secondary sludge (0.25 ± 0.04 μg g^?1 dry wt.). Respective TCC, TCS and MeTCS concentrations of 4.15 ± 0.77; 5.37 ± 0.97 and 0.058 ± 0.003 kg d^?1 are leaving the WWTP with the sludge and 0.13 ± 0.01; 0.24 ± 0.07 and 0.021 ± 0.002 kg d^?1 with the effluent that is discharged.     

Chemistry and Biology of the Potent Endotoxin from a Burkholderia dolosa Clinical Isolate from a Cystic Fibrosis Patient

This is the first report of the chemical and biological properties of the lipooligosaccharide (LOS) endotoxin isolated from Burkholderia dolosa IST4208, an isolate recovered from a cystic fibrosis (CF) patient in a Portuguese CF center. B. dolosa is a member of the Burkholderia cepacia complex, a group of closely related species that are highly problematic and opportunistic pathogens in CF. B. dolosa infection leads to accelerated loss of lung function and decreased survival. The structural determination of its endotoxin was achieved using a combination of chemistry and spectroscopy, and has revealed a novel endotoxin structure. The purified LOS was tested for its immunostimulatory activity on human HEK 293 cells expressing TLR‐4, MD‐2, and CD‐14. In these assays, the LOS showed strong proinflammatory activity.     

Metabolic pathways of the colonic metabolism of flavonoids (flavonols,flavones and flavanones) and phenolic acids

Flavonoids are metabolized by the gut microflora giving rise to a wide range of phenolic acids that may exert systemic effects in the body. Nevertheless, the colonic metabolism pathways and the function of the metabolites formed are poorly studied. In the present study, the individual colonic metabolism of three subclasses of flavonoids (flavonols, flavones and flavanones) and phenolic acids was evaluated. For this, seven standards of flavonoids (quercetin, quercetin–rhamnoside, quercetin–rutinoside, myricetin, luteolin, naringenin and kaempferol–rutinoside) and two phenolic acids (protocatechuic acid and gallic acid) were submitted to an in vitro fermentation model using rat colonic microflora. Simultaneously, a nuts–cocoa cream enriched with these standards of flavonoids was incubated and the colonic metabolism of these compounds was evaluated. The results showed that the greatest number of colonic metabolites came from the fermentation of quercetin and quercetin–rhamnoside, and the maximum concentration of fermentation products was observed after 48 h of fermentation. On the other hand, a smaller number of fermentation products were observed after the colonic fermentation of kaempferol–rutinoside, naringenin, luteolin and myricetin. The phenolic acids were slightly metabolized by the colonic microflora.     

Study of the thermal initiation of ammonium dinitramide (ADN) crystals and prills

Abstract

The thermal initiation by electron beam heating (and calibrated hot stage), of single crystals and prills of ADN, has been filmed / recorded in an Environmental Scanning Electron Microscope, from the formation of microscopic “reaction sites” (0.01 μm in diameter) to full crystal consumption. The transformations of the ADN prills and crystals were compared and recorded in real time at various magnifications (x10,000-100) and under different atmospheres (pure nitrogen and nitrogen/water vapour mixtures). The initiation characteristics of the prills and crystals were found to differ and are related to the microstructural characteristics produced by different prill manufacturing techniques namely, the “prilling tower” technique (Thiokol) and the “melt-stir” technique (CSD).     

Unraveling the Interaction between the LPS O‐Antigen of Burkholderia anthina and the 5D8 Monoclonal Antibody by Using a Multidisciplinary Chemical Approach,with Synthesis,NMR, and Molecular Modeling Methods

The interaction between the O‐chain from the lipopolysaccharide from Burkholderia anthina and a lipopolysaccharide‐specific monoclonal antibody (5D8) has been studied at high resolution by NMR spectroscopy. In particular, the 5D8‐bound epitope of the saccharide entity has been unraveled by a combination of saturation transfer difference (STD) and transferred NOESY (tr‐NOESY) experiments performed on the 5D8/polysaccharide complex. To dissect the fine details of the molecular recognition events, further experiments with simpler carbohydrate ligands were carried out. Thus, experiments were also performed with ad hoc synthesized trisaccharide and hexasaccharide O‐antigen repeating units. By using this multidisciplinary approach (chemical synthesis, NMR spectroscopy and molecular dynamics simulation), determination of the binding epitope and the contribution to the binding of the sugar units composing the O‐chain have been determined.     

Treatment of wastewater containing high phenol concentrations using stabilisation ponds enriched with activated sludge.

Treatment of wastewater containing high phenol concentrations (up to 4,000 mg/l, 1,600 kg/ha.d) in laboratory-scale stabilisation ponds enriched with activated sludge was studied. Phenol was biodegraded efficiently, even when fed as the sole carbon source. At influent concentrations of 1,000, 1,300, 1,600, 1,900, 2,500, 3,000 and 4,000 mg/l of phenol (loading rates of 400, 520, 640, 760, 1,000, 1,200 and 1,600 kg phenol/ha.d), the phenol removal efficiencies were 92, 89, 81, 81, 76, 65 and 22%, respectively. At 4,000 mg/l of phenol, the enriched ponds were significantly inhibited. The maximum phenol removal rate observed was 780 kg/ha.d, which is 7.7 times higher than the maximum value reported for attached-growth waste stabilisation ponds. All along the experiments, the enriched ponds showed removal rates 1.8-20.5 times higher than the values observed in control pond (not enriched). The results suggest that enrichment is an effective method to increase xenobiotic removal rates of stabilisation ponds.