Cozymase. A study of purification methods

Cozymase is one of the essential components of the complex enzyme mixture which effects alcoholic fermentation in the absence of living cells. The separation of the mixture into zymase and cozymase was first accomplished by Harden and Young [1] by means of ultrafiltration through a gelatin-impregnated Chamberland filter candle. The residue and filtrate as thus prepared possessed, separately, no fermentative action, but when mixed were found to produce a rapid fermentation. The active constituent of the residue was named zymase, while that constituent of the filtrate responsible for the reactivation of the residue was named cozymase. We studied the purification produced in our material by a variety of reagents. In the investigation we have repeated much of the work done by von Euler and Myrbäk [2], and several differences have been found, which appear difficult to explain solely upon the basis of the lower initial purity of our material. As certain of the experiments show distinct promise, we hope to be able to extend the work upon a material of considerably higher original purity, such as was employed by von Euler and Myrbäk

Specifying and Refining Internal Operations in Z

Abstract An important aspect in the specification of distributed systems is the role of the internal (or unobservable) operation. Such operations are not part of the interface to the environment (i.e. the user cannot invoke them), however, they are essential to our understanding and correct modelling of the system. In this paper we are interested in the use of the formal specification notation Z for the description of distributed systems. Various conventions have been employed to model internal operations when specifying such systems in Z. If internal operations are distinguished in the specification notation, then refinement needs to deal with internal operations in appropriate ways. Using an example of a telecommunications protocol we show that standard Z refinement is inappropriate for refining a system when internal operations are specified explicitly. We present a generalization of Z refinement, called weak refinement, which treats internal operations differently from observable operations when refining a system. We discuss the role of internal operations in a Z specification, and in particular whether an equivalent specification not containing internal operations can be found. The nature of divergence through livelock is also discussed. Keywords: Z; Refinement; Distributed Systems; Internal Operations; Process Algebras; Concurrency

Strategies for Consistency Checking

Viewpoint models of system development are becoming increasingly important. A major requirement for viewpoints modelling is to be able to check that the multiple viewpoint specifications are consistent with one another. The work presented in this report makes a contribution to this task. Our work is particularly influenced by the viewpoints model used in the ISO standardisation architecture for Open Distributed Processing. This report focuses on the issue of strategies for consistency checking. In particular, it considers how global consistency (between any arbitrary number of viewpoints) can be obtained from binary consistency (between two viewpoints). The report documents a number of different classes of consistency checking, from those that are very poorly behaved to those that are very well behaved. The report is intended as a companion to the work presented in [1] and it should be read in association with this document. In particular, the body of this report is a single chapter which should be viewed as additional to the chapters included in [1]. This report contains complete proofs of all relevant results, even though some of the results are obvious and some of the proofs are trivial. A much compressed version of the report is being submitted for publication. Thus, the main value of this report is as a reference document for readers who require a complete presentation of the technical. [1] E. Boiten, H. Bowman, J. Derrick and M. Steen ''Cross Viewpoint Consistency in Open Distributed Processing (Intra Language Consistency)'', Technical Report, Computing Laboratory, University of Kent at Canterbury, report No. 8-95, 1995. Phone: +44 1227 827913, Fax: 44 1227 762811 Email: H.Bowman,E.A.Boiten,J.Derrick,[email protected]

Unification and multiple views of data in Z

This paper discusses the unification of Z specifications, in particular specifications that maintain different representations of what is intended to be the same datatype. Essentially this amounts to integrating previously published techniques for combining multiple viewpoints and for combining multiple views. It is shown how the technique proposed in this paper indeed produces unifications, and that it generalises both previous techniques

Unity and the holiness churches : ǂb a study of moves toward unity among selected American Protestant denominations affiliated with the National Holiness Association

https://place.asburyseminary.edu/ecommonsatsdissertations/2180/thumbnail.jp

Changing Consumer Food Prices: A User's Guide to ERS Analyses

USDA's Economic Research Service (ERS) uses different economic models to estimate the impact of higher input prices on consumer food prices. The present study compares three ERS models. In the first two models, neither consumers nor food producers respond to market prices. We refer to these two models as short-run models. In the third model, both consumers and food producers respond to changing prices, and we refer to this model as a long-run model. Given published parameter estimates, we simulate the impact of a higher energy price on consumer food prices, and our empirical findings are consistent with our understanding of market responses. In the short run, we find that the full effect of an increase in the price of energy is fully (or nearly fully) passed on to consumers, because neither food producers nor consumers can immediately respond to changing prices. In the long run, however, the price response of food producers and consumers serves to mitigate the increase in consumer food prices.price-spread model, input-output model, variable-proportions model, food prices, energy prices, input prices, Demand and Price Analysis,