As landscapes change continuously in a more or less chaotic way, the concept of sustainable landscapes could be viewed as a utopian goal. New landscapes emerge with changing life-styles. Decision making for landscape planning, conservation and management use the concept of sustainability widely. To make it operational, many new associated and more specific concepts have been proposed such as natural and social capital, conservation economy and quality of life capital. Most of these are inspired by economic thinking and rarely refer directly to the landscape. This article reviews the background and meaning of these concepts and shows that landscape is not seen here as an integrating, holistic concept. As landscape changes, also its meaning and significance changes and consequently its management.

Sustainable landscapes: contradiction, fiction or utopia?

Two-dimensional graphene monolayers and bilayers exhibit fascinating electrical transport behaviors. Using infrared spectroscopy, we find that they also have strong interband transitions and that their optical transitions can be substantially modified through electrical gating, much like electrical transport in field-effect transistors. This gate dependence of interband transitions adds a valuable dimension for optically probing graphene band structure. For a graphene monolayer, it yields directly the linear band dispersion of Dirac fermions, whereas in a bilayer, it reveals a dominating van Hove singularity arising from interlayer coupling. The strong and layer-dependent optical transitions of graphene and the tunability by simple electrical gating hold promise for new applications in infrared optics and optoelectronics.

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Gate-Variable Optical Transitions in Graphene

Chemical composition, antioxidant and antimicrobial activities of essential oil obtained from Ferula assa-foetida oleo-gum-resin: effect of collection time.

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of the project was to prepare new catalyst systems, which would perform chemical reactions in an enantioselective manner so as to produce only one of the possible optical isomers of the product molecule. We have investigated the use of lanthanide metals bearing both diolate and Schiff-base ligands as catalysts for the enantioselective reduction of prochiral ketones to secondary alcohols. The ligands were prepared from cheap, readily available starting materials, and their synthesis was performed in a “modular” manner such that tailoring of specific groups within the ligand could be carried out without repeating the entire synthetic procedure. In addition. Tve have developed a new ligand system for Group IV and lanthanide-based olefin polymerization catalysts. The ligand system is easily prepared from readily available starting materials and offers the opportunity to rapidly prepare a wide range of closely related ligands that differ only in their substitution patterns at an aromatic ring. When attached to a metal center, the ligand system has the potential to carry out polymerization reactions in a stereocontrolled manner. Background and Research Objectives The modern pharmaceuticals and fine chemical industries are heavily reliant upon the ability to produce biologically active organic compounds (antibiotics, flavorings, pesticides, anesthetics, sweeteners etc.) of high optical (enantiomeric) purity. At one time, many drugs were supplied as racemic mixtures (containing equal quantities of both enantiomers) with the assumption that one enantiomer would perform the desired therapeutic function while the other would be harmlessly excreted. However, the catastrophic effects of the drug Thalidomide, sold in the 1960s as a racemic mixture, were traced to the supposedly benign (S)-isomer of the drug and since then the enantiomeric purity of many pharmaceutical products has been controlled by federal regulations. accomplished in one of two ways: (a) preparation of a racemic mixture followed by The preparation of a single enantiomer of a chiral organic molecule can generally be mechanical or chemical separation of the two enantiomers or (b) enantioselective synthesis in which only the target isomer is produced. The majority of pharmaceuticals are currently produced using the first of these methods, with the enantiomers often being separated by *Principal Investigator, email: jwatkin@lanl.gov

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Asymmetric catalysis in organic synthesis

Finding a suitable site to dispose solid waste is a difficult task for municipality because it is necessary to consider the different factors and criteria in the landfill siting process. In this study, in order to consider all parameters, a combination of Geographic Information System (GIS) and the Analytic Hierarchy Process (AHP) was used for landfill site selection. For the purpose of making decisions in landfill site selection a hierarchy structural was formed and different parameters have been identified, including distance to groundwater, distance to surface water, sensitive ecosystems, land cover, distance to urban and rural areas, land uses, distance to roads, slope, soil type and distance to waste generation places. At first, the rating method was used to evaluate each criterion individually. Then, the relative importance of criteria to each other was determined by an analytic hierarchy process (AHP). Simple Additive Weighting (SAW) method was applied to evaluate the land suitability. The results showed that 38% of the study area have high suitability for land filling. Finally, five sites were a candidate for field investigation with more details.

Landfill site selection using GIS and AHP: a case study: Behbahan, Iran

Functional properties of each enzyme strictly depend on immobilization protocol used for linking enzyme and carrier. Different strategies were applied to prepare the immobilized derivatives of Rhizomucor miehei lipase (RML) and chemically aminated RML (NH2-RML). Both RML and NH2-RML forms were covalently immobilized on glyoxyl sepharose (Gx-RML and Gx-NH2-RML), glyoxyl sepharose dithiothreitol (Gx-DTT-RML and Gx-DTT-NH2-RML), activated sepharose with cyanogen bromide (CNBr-RML and CNBr-NH2-RML) and heterofunctional epoxy support partially modified with iminodiacetic acid (epoxy-IDA-RML and epoxy-IDA-NH2-RML). Immobilization varied from 11% up to 88% yields producing specific activities ranging from 0.5 up to 1.9 UI/mg. Great improvement in thermal stability for Gx-DTT-NH2-RML and epoxy-IDA-NH2-RML derivatives was obtained by retaining 49% and 37% of their initial activities at 70 °C, respectively. The regioselectivity of each derivative was also examined in hydrolysis of fish oil at three different conditions. All the derivatives were selective between cis-5,8,11,14,17-eicosapentaenoic acid (EPA) and cis-4,7,10,13,16,19-docosahexaenoic acid (DHA) in favor of EPA. The highest selectivity (32.9 folds) was observed for epoxy-IDA-NH2-RML derivative in the hydrolysis reaction performed at pH 5 and 4 °C. Recyclability study showed good capability of the immobilized biocatalysts to be used repeatedly, retaining 50–91% of their initial activities after five cycles of the reaction.

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Fine Modulation of the Catalytic Properties of Rhizomucor miehei Lipase Driven by Different Immobilization Strategies for the Selective Hydrolysis of Fish Oil

https://link.springer.com/content/pdf/10.1007%2Fs10600-009-9241-1.pdf

Maryam Yousefi

Papers

Fine Modulation of the Catalytic Properties of Rhizomucor miehei Lipase Driven by Different Immobilization Strategies for the Selective Hydrolysis of Fish Oil

Chemical composition of the essential oil of Tanacetum turcomanicum and T. canescens from Iran

A new triterpene from Salvia xanthocheila Boiss.

A new highly hydroxylated triterpene from Salvia atropatana Bunge

Disulphides in the volatile oil of Ferula behboudiana Rech. f. & Esfand.