Yeast iso-l-cytochrome c: Genetic analysis of structural requirements

AbstractWe describe the use of classical and molecular genetic techniques to investigate the folding, stability, and enzymatic requirements of iso-l-cytochrome c from the yeast Saccharomyces cerevisiae. Interpretation of the defects associated with an extensive series of altered forms of iso-l-cytochrome c was facilitated by the recently resolved three dimensional structure of iso-l-cytochrome c [(1987) J. Mol. Biol. 199, 295–314], and by comparison with the phylogenetic series of eukaryotic cytochromes c. Residue replacements that abolish iso-l-cytochrome c function appear to do so by affecting either heme attachment or protein stability; no replacements that abolish electron transfer function without affecting protein structure were uncovered. Most nonfunctional forms retained at least partial covalent attachment to the heme moiety; heme attachment was abolished only by replacements of Cys19 and Cys22, which are required for thioether linkage, and His23, a heme ligand. Replacements were uncovered that retain function at varying levels, including replacements at evolutionarily conserved positions, some of which were structurally and functionally indistinguishable from wild type iso-l-cytochrome c

Aggregates: Digital design for design

This paper discusses an educational design methodology for undergraduate studio instruction, which uses a systematic and research based design approach. Based on Lars Spuybroek's methodology that was originally developed as a one-year graduate and postgraduate studio, a new method for undergraduate teaching has been developed. The paper will discuss Spuybroek's methodology, as developed for the graduate and postgraduate program, and explain its adaption for undergraduate studio instruction. Spuybroek's approach is based on a model that starts with research in systems in general that is them tuned to a certain set of architectural questions and developed into parametric buildings in a stepwise procedure by delaying the specifics of site and program

Junk: Design build studio

The paper presents a design build studio that investigates the role of waste as building material and develops a proposal for an installation that uses CAAD and CAM tools in combination with traditional fabrication tools to design and build an installation out of waste materials. The paper describes the concept development and the construction process through the help of computational tools. Recycling is in the process of becoming an integral part of sustainable architecture. However, there are very few digital design projects that use re-used or recycled materials in combination with their architectural and aesthetic qualities and potentials. The potential of such an investigation is explored within a design build studio. What is junk? What is a building material? What are the aesthetics of junk

Digital Girih, a Digital Interpretation of Islamic Architecture

The relation between texture, pattern and massing is a fundamental question in architecture. Classical architecture, as Leon Battista Alberti states in De Re Aedificatoria, Book VI, Chapter 2, is developed through massing and structure first, texture is added afterwards to give the bold massing and structure beauty [I]. This hierarchy has of course been challenged throughout architecture history. This paper will provide a different thinking of the relationship of massing and texture in Islamic Architecture from a digital point of view. An analysis of Islamic patterns challenged this relationship in Islamic architecture. Digital design and fabrication methods for a series of studies and an installation were used to respond to the findings of the analysis

Open Pattern

The paper explores MEL scripting as a design methodology and reports on the findings of its implementation as an introduction course in design computing for undergraduate and graduate students at the Architecture School at Georgia Institute of Technology. The course is structured into two parts: In the first part different variations of scripts are developed to generate three-dimensional patterns. In the second part these patterns are classified, interpreted and tested towards architecture

Math Objects

The paper discusses mathematical form generation as an academic methodology to develop new approaches to architectural design.  The academic design studio “Math objectsi investigates the relationship between complex 3d-surfaces and mathematics in order to expand the formal repertoire of architecture. It claims that the process of form generation can be seen as an autonomous entity, which is independent from an overall strategy or any a priori meaning. Architecture has always originated from a concept, eventually progressing towards a certain form. This methodology has been reversed. The paper discusses two studios undertaken in the last year, led by Daniel Baerlecken and Olaf Kobiella at the TU Braunschweig, Germany.

Microwave assisted catalytic reduction of sulfur dioxide with methane over MoS2 catalysts

The catalytic reduction of sulfur dioxide with methane to form carbon dioxide and sulfur has been studied over MoS2/Al2O3 catalysts. The reaction has been found to occur with microwave (2.45 GHz) heating at recorded temperatures as much as 200°C lower than those required when conventional heating was used. An activation energy of 117 kJ mol?1 has been calculated for the conventionally heated reaction, but an Arrhenius analysis of the data obtained with microwave heating was not possible, probably because of temperature variations in the catalyst bed. The existence of hot spots in the catalysts heated by microwave radiation has been verified by the detection of ?-alumina at a recorded temperature some 200°C lower than the temperature at which the ?- to ?-alumina phase transition is normally observed. Among four catalysts prepared in different ways, a mechanically mixed catalyst showed the highest conversion of SO2 and CH4 for microwave heating at a given temperature. Supported catalysts, sulfided either by conventional heating or under microwave conditions, showed little difference in the extent of SO2 and CH4 conversions. The highest conversions to carbon dioxide and sulfur, combined with low production of undesirable side products, was obtained when the molar ratio of SO2 to CH4 was equal to two, the stoichiometric ratio

Oscillatory behaviour during the partial oxidation of methane over cobalt wires and foils

The oscillatory behaviour over cobalt wire and foil catalysts was examined at atmospheric pressure under various reaction temperatures and argon/methane/oxygen feed gas compositions for the partial oxidation of methane. Rough and porous oxide layers on the catalyst surface were confirmed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The results obtained from the experimental studies indicated that the oscillatory behaviour exhibited during methane oxidation was related to the behaviour of the catalyst surface switching back and forth from the reduced state to the oxidised state. The reduction of the oxide layer followed by the almost immediate re-oxidation of the metal can be accounted for only if the oxide layer formed by oxidation is different from the oxide layer existing during reduction