Airborne Communications in Operation Market Garden

Operation Market Garden, Field Marshal B.L.M. Montgomery’s grand attempt to end the war in 1944, has been ceaselessly analysed in an attempt to understand the reasons for its failure. Factors such as the distance of the drop zones from the objectives in Arnhem, the delay in resupply, the presence of strong German forces in the area, as well as the slow progress of XXX Corps in linking the airborne bridgeheads, are some of the main reasons cited for the failure of the operation. Another element often raised has to do with the failure of communications equipment at Arnhem. Peter Harclerode, in his book, Arnhem: A Tragedy of Errors, puts it bluntly: “Much of the blame for 1st Airborne Division’s demise has been laid at the door of signals failure as well as the unsuitability of radio equipment issued to the division as well as its failure to work satisfactorily under the condition in which it was employed.” Lewis Golden, the adjutant of Divisional Signals during the operation argues that this was not the case. Signals actually worked better than could be expected and that communications failure was not the principal reason for defeat at Arnhem. This article attempts a comprehensive survey of the role of communications and answers the question, “How far were poor communications responsible for the failure of Market Garden?” In particular, how far did poor communications contribute to the failure of 1st Airborne Division to consolidate a bridgehead at the Arnhem road bridge

The ester hydrolytic and synthetic activities of X-prolyl dipeptidyl peptidase from Streptococcus thermophilus : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Biochemistry at Massey University, New Zealand

X-prolyl dipeptidyl peptidase (EC 3.4.14.11), or PepX, is a dipeptidase found in most dairy lactic acid bacteria that hydrolyses N-terminal dipeptides from larger peptides where proline is the residue penultimate to the scissile bond. It has recently been found that PepX will also catalyse the hydrolysis of some chromogenic esters and synthesise esters via an acyltransferase mechanism that uses ethanol as the acceptor molecule and tributyrin as the donor molecule. In this study, the pepX gene from Streptococcus thermophilus strain B2513 was cloned and sequenced. This sequence was found to differ in several positions from the recently published pepX sequence of S.thermophilus strain ACA-DC4. None of the observed substitutions occurred in the catalytic domain of the enzyme, all being localised to the C-terminal β-sheet domain. An activity assay using a chromogenic peptide substrate with tributyrin as an was used to prove that PepX binds peptide substrates and acylglycerides at the same binding site, implying that the same catalytic machinery carries out both peptide hydrolysis and activities involving acylglycerides. PepX was found to form esters only from the acylglyceride tributyrin, and was not active on any of the larger triglycerides tested. The chemical mechanism for this ester formation is proposed to involve the direct transfer of an acyl group from the donor to an acceptor, rather than acyl hydrolysis followed by the separate transfer of a carboxylic acid product onto an acceptor, as the enzyme does not form esters when provided with butyric acid and ethanol. PepX was found to be incapable of hydrolysing milkfat and tributyrin in aqueous solution. This contrasts with the ability of PepX to hydrolyse the synthetic ester p-nitrophenyl butyrate, which probably is a reflection of the lability of the ester bond in this substrate. The results of this study show that PepX is a peptidase that has a secondary acyltransferase activity, with no hydrolase activity on natural acylglyceride substrates

A software tool for simulating practical chemistry

A software package has been written to allow a user to build and manipulate a simple chemistry experiment. Using a toolbox of equipment the apparatus can be interactively designed and the necessary chemicals added from a database. Selection of the appropriate physical and reaction conditions allows the experiment to be run both in real and virtual time, snapshots of the experiment being stored for subsequent modification and replay. The structure of the reaction data file allows any reaction to be designed with yields and both forward and backward reaction rates. Thus, the user has the opportunity to experiment with the best apparatus layout, reactant composition and physical conditions in order to achieve an optimal result. Some extensions of the current software are discussed

Managing Wireless Networks in the Healthcare Sector: Emerging Experiences of Cultural Impacts

The existing body of knowledge has generally supported that organizational culture plays a significant role in shaping group identity, work pattern, communication schemes, and interpersonal relations; all of these cultural elements are important organizational factors that shape workplaces and operational routines. In the context of emerging information technology, it has also been suggested that organizational culture could affect IT implementation and management. However, little is known about how emerging information technology shapes organizational culture, which in turn helps reshape the organization as a whole. The purpose of this paper is thus to build empirical understanding of how IT in general and emerging wireless networks in particular reshapes organizational culture. Case studies conducted in two hospitals situated in southwest U.S.A. illustrated that the implementation of wireless networks indeed helped shape and/or reshape organizational culture in the healthcare sector and in turn enhance healthcare organizations’ competitiveness in the marketplace. For IT managers and practitioners in healthcare institutions, effective strategy to plan and manage emerging ITs such as wireless networks will thus have long-term implications on cultivating organizational culture that could eventually reshape workplace and competitiveness

Subdyadic square functions and applications to weighted harmonic analysis

Through the study of novel variants of the classical Littlewood-Paley-Stein $g$-functions, we obtain pointwise estimates for broad classes of highly-singular Fourier multipliers on $\mathbb{R}^d$ satisfying regularity hypotheses adapted to fine (subdyadic) scales. In particular, this allows us to efficiently bound such multipliers by geometrically-defined maximal operators via general weighted $L^2$ inequalities, in the spirit of a well-known conjecture of Stein. Our framework applies to solution operators for dispersive PDE, such as the time-dependent free Schr\"odinger equation, and other highly oscillatory convolution operators that fall well beyond the scope of the Calder\'on-Zygmund theory.Comment: To appear in Advances in Mathematic