Information and Dynamics: Sequences of Call Markets

This paper is part of a wider research project with the objective of creating computational testbeds for designing and testing new mechanisms—new economic and political institutions. Here we illustrate the power of such an approach by testing two call market designs in a repeated demand-supply environment. We find there to be significant differences in performance depending on the information provided to the traders between calls. In particular, we find that both dynamic and static performance is better, less volitility and higher gains from trade, if traders receive less information between calls.     

The influence of m-aminobenzoic acid on electrochemical synthesis and behavior of poly(aniline-co-(<Emphasis Type="Italic">m</Emphasis>-aminobenzoic acid)

Poly(aniline-co-(m-aminobenzoic acid)) was synthesized electrochemically at graphite electrode under galvanostatic conditions. Aqueous electrolyte for synthesis was consisted of HCl and different amount of aniline and m-aminobenzoic acid. The presence of the meta positioned carboxylic group in m-aminobenzoic acid influenced higher co-polymerization potential, different morphology and electrochemical behavior of copolymers compared to polyaniline. Electrochemical activity is achieved by proton exchange in neutral environment that can result in a faster charge/discharge process, which is in the case of PANI limited by slow anion exchange, making this material promising for consideration in super-capacitors and in biological system.     

Improving thermostability of phosphatidylinositol-synthesizing Streptomyces phospholipase D

Aimed to produce thermostable phosphatidylinositol (PI)-synthesizing phospholipase D (PLD), we initiated site-directed combinatorial mutagenesis followed by high-throughput screening. Previous site-directed combinatorial mutagenesis of wild-type Streptomyces PLD produced a mutant, DYR (W187D/Y191Y/Y385R) with PI-synthesizing ability. Deriving PI as a product of transphosphatidylation between phosphatidylcholine and myo-inositol, with myo-inositol in excess at high-temperature reaction conditions can increase yield due to enhanced solubility of this substrate. Thus, we improved DYR's thermostability by introduction of random mutations into selected amino acid positions having high B-factor. Screening of the libraries under restricted conditions yielded single-point mutants, specifically D40H, T291Y and R329G. Combinations of these point mutations yielded double (D40H/T291Y, D40H/R329G and T291Y/R329G) and triple (D40H/T291Y/R329G) mutants. PI synthesis at elevated temperatures pointed at D40H/T291Y as the most efficient enzyme. Circular dichroism analysis revealed D40H/T291Y to have increased melting temperature and postponed onset of thermal unfolding compared with DYR. Thermal tolerance study at 65°C confirmed D40H/T291Y's thermostability as its half-inactivation time was 8.7 min longer compared with DYR. This mutant had significantly less root-mean-square deviation change compared with DYR and showed no change in root-mean-square fluctuation when temperature shifts from 40 to 60°C, as determined by molecular dynamics analysis. Acquired different degrees of thermostability were also observed for several other DYR mutants.     

Tear fluid-eye drops compatibility assessment using surface tension

Objective: To evaluate the compatibility of commercially available eye drop surface tension with the tear film physiological range and to characterize commonly used ophthalmic excipients in terms of their surface activity under eye-biorelevant conditions.

Significance: There are a number of quality requirements for the eye drops (e.g. tonicity, pH, viscosity, refractive index) that needs to comply with the physiological parameters of the eye surface. However, the adjustment of surface tension properties of the eye drops to the normal range of surface tension at the air/tear fluid interface (40–46?mN/m) has received rather less attention thus far. Yet, the surface tension at the air/tear fluid interface is of vital importance for the normal function of the eye surface.

Methods: The surface tension compatibility of the isotonic aqueous solutions of commonly used ophthalmic excipients as well as 18 approved eye drops with the tear fluid have been evaluated using surface tension method.

Results: Each ophthalmic ingredient including the preservatives, solubilizing agents and thickening agents can influence the surface tension of the final formulation. In case of complex ophthalmic formulations one should also consider the possible interactions among excipients and consequent impact on overall surface activity. Out of 18 evaluated eye drops, three samples were within, 12 samples were below and three samples were above the physiological range of the tear fluid surface tension.

Conclusions: Our results provide a rationale for clinical studies aiming to assess the correlation between the eye drops surface tension and the tear film (in)stability.     

Quality of experience for unified communications: A survey

This paper presents a quality of experience (QoE) conceptual model to the context of unified communications (UC) through summary, classification, and discussion of multiple influence factors (IFs) and dimensions affecting it. A deep and comprehensive understanding of the IFs and their impact on QoE for a given service is an essential precondition for successful QoE management with the overall goal of prominently optimizing end‐user QoE, while making efficient use of network resources and maintaining a satisfied user base. The proposed conceptual model was used to conduct a qualitative meta‐analytical review of selected papers. The results of the qualitative review include various IFs, QoE dimensions, and key findings in the form of research recommendations for QoE in the context of UC.     

Copper-Sulfate Pentahydrate as a Product of the Waste Sulfuric Acid Solution Treatment

The aim of this study is synthesis of copper-sulfate pentahydrate from the waste sulfuric acid solution-mother liquor generated during the regeneration process of copper bleed solution. Copper is removed from the mother liquor solution in the process of the electrolytic treatment using the insoluble lead anodes alloyed with 6 mass pct of antimony on the industrial-scale equipment. As the result of the decopperization process, copper is removed in the form of the cathode sludge and is precipitated at the bottom of the electrolytic cell. By this procedure, the content of copper could be reduced to the 20 mass pct of the initial value. Chemical characterization of the sludge has shown that it contains about 90 mass pct of copper. During the decopperization process, the very strong poison, arsine, can be formed, and the process is in that case terminated. The copper leaching degree of 82 mass pct is obtained using H₂SO₄ aqueous solution with the oxygen addition during the cathode sludge chemical treatment at 80?°C?±?5?°C. Obtained copper salt satisfies the requirements of the Serbian Standard for Pesticide, SRPS H.P1. 058. Therefore, the treatment of waste sulfuric acid solutions is of great economic and environmental interest.     

Toward a positive-net-energy residential building in Serbian conditions

This article reports investigations of a residential building in Serbian conditions energized by electricity from photovoltaics (PVs), and the electricity grid. The building uses electricity to run its space heating system, lighting and appliances, and to heat domestic hot water (DHW). The space heating system comprises floor heaters, a water-to-water heat pump, and a ground heat exchanger. The PV system generates electricity that either may be consumed by the building or may be fed-in the electricity grid. The electricity grid is used as electricity storage. Three residential buildings are investigated. The first residential building has PVs that yearly produce smaller amount of electricity than the heating system requires. This is a negative-net energy building (NNEB). The second building has the PVs that produce the exact amount of electricity that the entire building annually needs. This is a zero-net energy building (ZNEB). The third building has PVs that entirely cover the south-facing roof of the building. This is a positive-net energy building (PNEB). These buildings are presented by a mathematical model, partially in an EnergyPlus environment. For all buildings, simulations by using EnergyPlus software would give the generated, consumed, and purchased energy with time step, and monthly and yearly values. For sure, these buildings would decrease demand for electricity during summer, however they will increase this demand during winter when there is no sun and start of space heating is required. Depending on the size of PV array this building will be either NNEB, or ZNEB, or PNEB. However it is crucial for such a building to be connected to the electricity grid. The smaller payback for investment in the PV array is obtained for buildings with larger size of PV array. The feed-in tariff for the generation of electricity in Serbia should be under the constant watch to be corrected accordingly for larger penetration of this technology in the Serbian market.     

Lipid Nanoparticle Technology for Delivering Biologically Active Fatty Acids and Monoglycerides

There is enormous interest in utilizing biologically active fatty acids and monoglycerides to treat phospholipid membrane-related medical diseases, especially with the global health importance of membrane-enveloped viruses and bacteria. However, it is difficult to practically deliver lipophilic fatty acids and monoglycerides for therapeutic applications, which has led to the emergence of lipid nanoparticle platforms that support molecular encapsulation and functional presentation. Herein, we introduce various classes of lipid nanoparticle technology and critically examine the latest progress in utilizing lipid nanoparticles to deliver fatty acids and monoglycerides in order to treat medical diseases related to infectious pathogens, cancer, and inflammation. Particular emphasis is placed on understanding how nanoparticle structure is related to biological function in terms of mechanism, potency, selectivity, and targeting. We also discuss translational opportunities and regulatory needs for utilizing lipid nanoparticles to deliver fatty acids and monoglycerides, including unmet clinical opportunities.