Yes
Since 2010 the Stonehenge Hidden Landscapes Project (SHLP) has undertaken extensive archaeological prospection across much of the landscape surrounding Stonehenge. These remote sensing and ...geophysical surveys have revealed a significant number of new sites and landscape features whilst providing new information on many previously known monuments. The project goal to integrate multimethod mapping over large areas of the landscape has also provided opportunities to re-interpret the landscape context of individual monuments and, in the case of the major henge at Durrington Walls, to generate novel insights into the structure and sequence of a monument which has attracted considerable research attention over many decades. This paper outlines the recent work of the SHLP and the results of survey at Durrington Walls that shed new light on this enigmatic monument including a site ‘hidden’ within the monument.
A model of multiphasic systems, based on the assumption of zero-order partition of substrates and products into the membranes, is applied to reversible mono-substrate and bi-substrate reactions ...catalysed by membrane-bound enzymes. Apart from replacement of single-phase kinetic constants by apparent kinetic constants, the derived kinetic expressions are formally identical with those for corresponding single-phase systems. The model confers to the apparent kinetic constants an experimentally verifiable meaning. For full characterization of membrane-kinetic systems, experiments at various concentrations of enzyme-embedding phospholipid are required. Extrapolation to zero phospholipid concentration of each Km app then yields the corresponding true kinetic constant characteristic of the membrane-bound enzyme and also provides a technique for determination of the membrane-partition constants. The procedure implies that the phospholipid content should be assayed for full characterization of membrane-bound enzymes. If, for practical reasons, the assays have to be limited to a single enzyme concentration, correction of the apparent kinetic constants is still possible provided the phospholipid concentration and the partition constants of the reactants are known. The model has permitted prediction of a number of previous observations reflecting the multiphasic nature of the systems. The assumptions, underlying the model, and their implications are examined as well as some commonly used experimental designs for determination of the type of enzymic site.
Specific lipid requirement for the activation of Azotobacter nitrogenase Ceuterick, F; Heremans, K. (Katholieke Univ., Leuven (Belgium). Lab. voor Fysiologie); Smedt, H. de
Archives internationales de physiologie et de biochimie,
(Apr 1977), 1977-Apr, 19770401, Letnik:
85, Številka:
2
Journal Article
It is shown that lipids are responsible for the breaks in the Arrhenius plots of Azotobacter nitrogenase. The physical evidence is that temperature at which the break occurs increases with increasing ...pressure by 20 K/1000 atm. This is in agreement with the pressure dependence of the transition temperature of several synthetic phospholipids. We also find the same pressure dependence for the broad transitions observed in Escherichia coli phosphatidylethanolamine and in the membrane lipids from Azotobacter itself. Detergents and phospholipase remove the break. Reconstruction can be performed only with specific phospholipids.
A new in-house developed three-dimensional scanning system for measuring electromagnetic fields close to devices and systems is presented. The scanning system is able to perform translations along a ...three-dimensional Cartesian grid with arbitrary grid size so that any electromagnetic field component can be measured with high accuracy and detail. A near-field scan of an AT motherboard and of a telecom subsystem is described to illustrate the performance of the scanning system. The measurements show that the scanning, system is an excellent diagnostic tool for the detection of EMC problems in an early stage of product development.
In this paper, the near-field radiation from printed circuit boards is studied quantitatively by means of a new in-house developed three-dimensional measurement set-up. Special attention is given to ...the development, characterization and calibration of the near-field probes. The performance of the whole measurement set-up is evaluated by comparing the calibrated measurements above a single microstrip line with simulated results. A very good agreement is observed. Moreover, by means of a two-dimensional near-field scan over a more complex printed circuit trace, the capabilities of the developed measurement set-up in order to locate and quantify the sources of radiated emission are highlighted.
