'A Holding, Uniting-Constant Friend': The Organ in Seventeenth-Century English Domestic Music

This thesis presents an investigation into the nature and use of the consort organ in English secular instrumental music of the seventeenth century with a view to informing present-day performance practice. Whilst the English string consort repertoire has been widely studied from the perspective of the viol and violin, the role of the organ and organist has remained neglected. This study seeks to redress this through the examination of manuscript sources, contemporary writing and extant instruments to illuminate a variety of performance practice issues. The development and organology of the instrument is considered, focussing particularly on the distinctive methods of construction and voicing that were designed to enhance the instrument’s role in playing with string ensembles. The contexts of chamber music at the court, in domestic establishments, and in theatres, choir schools and music meetings are examined from the perspective of the consort organ. Manuscript sources, contemporary historical sources and the consideration of extant instruments in relation to their original locations and associated repertoire are interrogated for performance practice information. The role of the consort organist, from both a musical and sociological standpoint, is also discussed with reference to contemporary sources. The findings reveal that seventeenth-century usage of the organ differed from present-day practice in relation to a number of key areas including pitch, temperament, registration and expression, and that the organist’s role encompassed a wide range of skills that are rarely explored in modern performances or editorial realisations. The study concludes that a revised approach to the use of the consort organ in present-day performance of the seventeenth-century English consort repertoire is required

Interim report on the analysis of the microwave power module

The results of a traveling wave tube multistage depressed collector (TWT-MDC) design study in support of the DARPA/DoD Microwave Power Module (MPM) Program are described. The study stressed the MDC as a key element in obtaining the required high overall efficiencies in the MPM application. The results showed that an efficient MDC, utilizing conventional design and fabrication techniques can be designed for the first generation MPM TWT, which permits a package one wavelength thick (.66 in. at 18 GHz). The overall TWT efficiency goal of 40 percent for electronic countermeasure (ECM) applications appears to be readily achievable. However, the 50 percent goal for radar applications presents a considerable challenge

New Insights Into Sunflower (Helianthus annuus L.) FatA and FatB Thioesterases, Their Regulation, Structure and Distribution

Sunflower seeds (Helianthus annuus L.) accumulate large quantities of triacylglycerols (TAG) between 12 and 28 days after flowering (DAF). This is the period of maximal acyl-acyl carrier protein (acyl-ACP) thioesterase activity in vitro, the enzymes that terminate the process of de novo fatty acid synthesis by catalyzing the hydrolysis of the acyl-ACPs synthesized by fatty acid synthase. Fatty acid thioesterases can be classified into two families with distinct substrate specificities, namely FatA and FatB. Here, some new aspects of these enzymes have been studied, assessing how both enzymes contribute to the acyl composition of sunflower oil, not least through the changes in their expression during the process of seed filling. Moreover, the binding pockets of these enzymes were modeled based on new data from plant thioesterases, revealing important differences in their volume and geometry. Finally, the subcellular location of the two enzymes was evaluated and while both possess an N-terminal plastid transit peptide, only in FatB contains a hydrophobic sequence that could potentially serve as a transmembrane domain. Indeed, using in vivo imaging and organelle fractionation, H. annuus thioesterases, HaFatA and HaFatB, appear to be differentially localized in the plastid stroma and membrane envelope, respectively. The divergent roles fulfilled by HaFatA and HaFatB in oil biosynthesis are discussed in the light of our data.España MINECO y FEDER Projects AGL2014- 53537-R y AGL2017-83449-