On the existence of generalized inverse estimators in a singular system of equations

This paper deals with estimation problems in the context of singular systems of equations. It provides the necessary and sufficient conditions for the existence of restricted estimators as a routine extension of the standard theory of restricted least squares estimation. The paper also provides the means for carrying out tests of hypotheses on subsets of restrictions imposed on the system by explicitly providing an expression for the (appropriate) Lagrange multipliers.     

A spectrophotometric method for the direct recording of dioldehydrase activity

Zusammenfassung Es wird eine raschere und empfindlichere Methode zur Bestimmung der Aktivität von Dioldehydrase beschrieben.     

A test of space-time arma modelling and forecasting of hotel data

This paper describes the application of space-time ARMA modelling to demand-related data from eight hotels from a single hotel chain in a large US city. Important spatial characteristics of the space-time process are incorporated into the model using a simple weighting matrix based on driving distances between the hotels. Using a hold-out sample, the forecasting performance of this space-time approach was found to be superior to eight separate univariate ARMA models.     

IgG purification to measure the level of an iodinated thyroglobulin peptide,the 3,5,3′,5′ tetraiodo-l-tyrosyl-l-tyrosine in human serum

Summary Antibodies reacting with 3,5,3,5 tetraiodo-l-tyrosyl-l-tyrosine (I₂Tyr-I₂Tyr) were elicited in rabbits by immunization with an oxidized yeast conjugate coupled with I₂Tyr-I₂Tyr. Ion-exchange chromatography was used to purify immunoglobulins, in order to improve the specificity in measurement of I₂Tyr-I₂Tyr level in patient serum. IgG binding capacity versus I₂Tyr-I₂Tyr was considerably increased after immunoglobulin purification.Acknowledgments. The authors with to thank Mrs M. Ollier for her valuable technical assistance.     

A new analytical framework for the understanding of Diophantus’s Arithmetica I–III

This study is the foundation of a new interpretation of the introduction and the three first books of Diophantus’s Arithmetica, one that opens the way to a historically correct contextualization of the work. Its purpose, as indicated in the title, is to renew the traditional discussion on the methods of problem-solving used by Diophantus, through the detailed exposition of a new analytical framework that aims to give an account of the coherence and progressive nature of the material included in the three first books of the Arithmetica. One outcome of this new ‘toolbox’ is a new conspectus of the problems and solutions contained in the latter, which is presented in appendix. The first part of the article clarifies, as a necessary preliminary, the key notions and terminology underlying our analysis. Among these new concepts is the notion of “method of invention,” which accounts in general for any way, by which “positions” (hypostaseis) are used in the Arithmetica. The next part proposes a complete inventory of the various methods of invention found in the three first books. Finally the last part presents the above mentioned conspectus and proposes a series of preliminary conclusions that can be drawn from it.     

Rehabilitating theory: refusal of the ‘bottom-up’ construction of scientific phenomena

In this paper I inquire into Bogen and Woodward’s (1988) data/phenomena distinction, which in a similar way to Cartwright’s construal of the model of superconductivity (1995)—although in a different domain—argues for a ‘bottom-up’ construction of phenomena from data without the involvement of theory. I criticise Bogen and Woodward’s account by analysing their melting point of lead example in depth, which is usually cited in the literature to illustrate the data/phenomenon distinction. Yet, the main focus of this paper lies on Matthias Kaiser’s (1995) case study of the plate tectonic revolution, the most extensive case study that has been put forth to support the bottom-up construction of phenomena. On the basis of new historical evidence, which has been overlooked not only by Kaiser but also by the entire historical literature on the plate tectonic revolution, I demonstrate that phenomena are not constructed from the bottom-up but rather, admittedly counter-intuitively, from the top-down.