Production of fungal lipases using wheat bran and soybean bran and incorporation of sugarcane bagasse as a co-substrate in solid-state fermentation

Fungal strains were screened for lipase producing activities and 10 strains were classified as good producers. Aspergillus sp., Fusarium sp., and Penicillium sp. exhibited the highest activities when fermented in wheat bran (WB) and soybean bran (SB). No fungal growth was observed using sugarcane bagasse (CB). An experimental design was applied to incorporate CB into the fermentation process for lipase production by Aspergillus sp. and Penicillium sp., and to evaluate the best moisture content for the substrate. Strains studied achieved maximum lipase activities with 25% CB combined with 75% WB or SB at 40% moisture content. The highest lipase activities were observed for WB and SB, and for SB combined with CB using Aspergillus sp. Fermentation of 96 h was the optimum period for enzyme production.     

Protective effect of estrogens and catecholestrogens against peroxidative membrane damagein vitro

The antioxidant effects of natural estrogens (estrone E₁; 17β-estradiol), synthetic estrogens (17α-ethynylestradiol, EE₂; mestranol, MES; diethylstilbestrol, DES) and catechle-strogens (2-hydroxyestradiol; 4-hydroxyestradiol 4-OHE₂) on lipid peroxidation induced by different means in rat liver microsomes were investigated. The extent of lipid peroxidation was determined by measuring thiobarbituric acid reactive substances. Prooxidants included Fe³⁺/ADP/reduced NADPH, Fe²⁺/ascorbate,tert-butyl hydroperoxide (t-BOOH) and 2,2′-azobis (2-amidinopropane) (AAPH). Estrogens and catecholestrogens decreased lipid peroxidation in all four systems tested. In the iron/ascorbate model it was shown that (i)-OHE₂ and DES had analogous patterns of inhibition, irrespective of the presence of NADPH or the functional integrity of the microsómes, and (ii) the antioxidant activities of E₁, EE₂ and MES were dependent on the assay conditions with the activity being markedley higher when estrogen metabolism was favored. When peroxidation was initiated by the peroxyl radical generator AAPH, the inhibitory effects observed were least pronounced. Our data also showed that, in each of the systems, all inhibitors displayed the same order of inhibitory potency with DES and catecholestrogens being the most potent antioxidants under all experimental conditions used. The present results confirm earlier findings and point toward a link between estrogen metabolism and estrogen antioxidant activity. The data also indicate that estrogens and catecholestrogens interact with the peroxidative process at different levels with their interactions with iron or the metal-derived species being the most important modes of inhibition.     

Electrical conductivity and rheology of carbon‐filled liquid crystal polymer composites

One emerging market for electrically conductive resins is for bipolar plates for use in fuel cells. Adding carbon fillers to thermoplastic resins increases composite electrical conductivity and viscosity. Current technology often adds as much of a single type of carbon filler as possible to achieve the desired conductivity, while still allowing the carbon‐filled thermoplastic matrix material to be extruded and molded into a bipolar plate. In this study, varying amounts of two different types of carbon, one carbon black and one synthetic graphite, were added to Vectra A950RX liquid crystal polymer. The resulting single filler composites were then tested for electrical conductivity and rheological properties. The electrical conductivity followed that typically seen in polymer composites with a percolation threshold at 4 vol % for carbon black and at 15 vol % for synthetic graphite. Over the range of shear rates studied, the viscosity followed a shear‐thinning power law model with power‐law exponent (n ? 1) = ?0.5 for neat Vectra A950RX and (n ? 1) = ?0.7 for highly filled composite materials. Viscosity increased with increasing filler volume fraction for all shear rates. The viscosity–enhancement effect was more rapid for the composites containing carbon black when compared with those containing synthetic graphite. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2680–2688, 2006     

Vertical versus scanning lidar measurements in a horizontally homogeneous atmosphere

This study compares the aerosol backscatter and extinction coefficients retrieved from vertical elastic and Raman channels with those derived from measurements with multiangle elastic channels. Retrievals from simulated vertical signals at 355 nm, 387 nm, 532 nm, and 607 nm are compared with those from multiangle measurements (at 15 elevation angles) at 355 nm and 532 nm. The atmosphere is considered horizontally homogeneously stratified. For the backscatter coefficient, the Raman backscatter solution and the multiangle solution are considered. For the extinction coefficient, retrievals from the Raman channel and multiangle measurements are compared. The comparison shows that in the presence of horizontal homogeneity, multiangle measurements provide more reliable results, especially for the aerosol extinction coefficient. The uncertainty in the measured signals is considered in an alternative approach to quantify the relative error of the retrieved profiles with respect to the models (linear regression between retrieval and model).     

Application of corporate social responsibility approach in Bulgaria to support sustainable tourism development

The rapidly developing tourism industry in Bulgaria in the last 15?years, especially at the Black sea coast, contributed to an entire change in the accommodation sector. The growth was due to unseen construction of new accommodation facilities and entire renovation of the existing ones. At the same time the tourism industry suffers from many social problems: lack of staff, shortage of qualified staff especially in the high-star hotels, very high rate of turnover, flow of Bulgarian staff abroad. The bigger mobility of the employees is facilitated by the seasonal character of the industry, knowledge of foreign languages, difference in payments, as well as in the nature of work. Overall, this leads to lost training investments, reduces the incentives for employers to provide training, causes lower quality services in hotels, and finally impacts negatively the competitiveness of the hotel sector in Bulgaria and its sustainable development. The paper presents the practical experience and conclusions from a corporate social responsibility (CSR) assessment in 25 Bulgarian hotels regarding the social issues of the CSR: human resource management, occupational safety and health, human and labour rights, stakeholder and community involvement, customer satisfaction. The most important social problems identified are: deficiency in management skills, deficiency in organised (external) stakeholder dialogue, lack of qualified staff in certain professions, lack of investment in training, high turnover, low motivation, conflicts related to wage levels, overtime, etc. A set of key performance indicators related to social responsibility is suggested and analysed. The benchmarking process is discussed and exemplary benchmarks are quoted. The most frequently proposed measures by the hotel CSR teams to improve the social responsibility in the hotels are reviewed.     

“MORE BUZZWORDS THAN ANSWERS” — TO SIDEWALK LABS IN TORONTO

Many articles have appeared in mainstream media and in techoriented venues about Sidewalk Labs’ ideas for a new hightech neighbourhood in Toronto (a project named Sidewalk Toronto). By and large, international commentary has focused on the opportunities and risks of giving over control over many city planning decisions to a private data-oriented corporation, with people lining up for or against “smart city” ideas, in general. This article will set aside generalities about “smart cities” and technology, and instead pose a few questions about the particulars of Sidewalk Toronto project. The first question concerns the striking lack of transparency of the agreement between Sidewalk Labs (a Google sister company) and Waterfront Toronto, the public authority promoting the project, which is not directly accountable to the city or the citizens. The second question concerns the equally striking ambiguity about which parcel of land is being sought by Sidewalk Labs — an ambiguity that suggests a worrying lack of concern, on the tech company’s part, about both local planning law and local real estate realities. The third set of concerns is about the ownership of the data that appears to be Sidewalk Labs’ real interest. Fourthly, problems in the contract award and procurement mechanisms will be raised. Finally, even though the agreement has not yet been seen even by city council, the process so far and the statements by both parties raise serious concerns about accountability, the fifth point raised in this article.