The present paper is an extract from a thesis concerning the debate between bradley and russell on the nature of relations. it concerns only the most general points of interaction - the positive influence of bradley upon russell with respect to psychologism, logic, and constructions; the negative influence: russell's work seen as a reaction to bradley. the intention is to show that bradley was an extremely strong influence in russell's development hardly worthy of the disregard which russell showed him.

ABSTRACTDiffraction gratings are famously associated with Henry Rowland of Johns Hopkins University but there were precursors. Although gratings were first made and used in Europe, reliable machines for ruling gratings were developed in the USA, and two men, Lewis Rutherfurd and William Rogers, tackled the problem before Rowland. Rutherfurd, a wealthy independent astronomer, designed and built the first screw-operated engine for ruling diffraction gratings, the fore-runner of almost all subsequent ruling engines. With it he and his assistant D. C. Chapman (...) ruled many gratings which he generously distributed to practising scientists, thereby materially advancing the science of spectroscopy. Rogers was a Harvard astronomer who developed an interest in the ruling of fine lines on glass that led him to construct a ruling engine with which he investigated the causes of the errors in the rulings he had examined. He continued to seek improvements with a second engine designed for ruling diffraction gratings. He ceased developing this engine when Rowland’s excellent gratings began to be available, concentrating instead on related problems to which he could apply the knowledge and skills he had gained, but his investigations assisted Rowland and other later ruling engine builders. This paper brings together what is known about the ruling engines of Rutherfurd and Rogers, their development, the gratings they produced, their quality and the work that was done with them, and assesses and compares their achievements and the impacts of the work of these two men. (shrink)

The present paper is an extract from a thesis concerning the debate between bradley and russell on the nature of relations. it concerns only the most general points of interaction - the positive influence of bradley upon russell with respect to psychologism, logic, and constructions; the negative influence: russell's work seen as a reaction to bradley. the intention is to show that bradley was an extremely strong influence in russell's development hardly worthy of the disregard which russell showed him.

SummaryDiffraction gratings have contributed enormously to modern science. Although some historians have written about them, there is much more to be brought to light. This paper discusses their development and use in the period up to about 1880 before Rowland began to produce them. Rittenhouse described the action of a diffraction grating in 1786, but no explanation was possible until the wave theory of light was developed. Fraunhofer discovered the dark lines in the solar spectrum in 1814, and then investigated (...) diffraction, producing the first ruled gratings, making detailed measurements and calculating the wavelengths of prominent spectral lines. After Bunsen and Kirchhoff showed the association between spectral lines and chemical elements there was an upsurge of interest in measuring wavelengths. The gratings used in this work almost all came from one source, a relatively unknown instrument maker called Nobert, who made them by an extremely laborious process using a machine he had built himself. The most significant wavelength measurements were made by Ångström, but Mascart, Van der Willigen, Stefan, Ditscheiner and Cornu also did important work. Nobert gratings were investigated by Quincke, copied photographically by Rayleigh, and were known and discussed in the USA. Nobert's work helped to advance spectroscopy much more than has been acknowledged. (shrink)

We consider Berezin's algebraic considerations regarding the quantization of phase space polynomials. After making a connection with Prugovečki's stochastic quantization approach, we give a particular construction of Berezin's L-Kernel in terms of Prugovečki's ξ-functions.

A major problem in developing an effective gene therapy for the nervous system lies in understanding the principles that maintain or turn off the expression of genes following their transfer into the CNS.

In “Two Concepts of Liberty” Berlin notes the protean nature of the word “freedom” and then systematically proceeds to narrow its range of meanings. In the process, Berlin eliminates much of what most people, in everyday communication, regard as freedom, believing that this is in the best interest of intellectual clarity. As he puts it: [N]othing is gained by a confusion of terms. To avoid glaring inequality or widespread misery I am ready to sacrifice some, or all, of my freedom: (...) I may do so willingly and freely: but it is freedom that I am giving up for the sake of justice or equality or the love of my fellow men. I should be guilt‐stricken, and rightly so, if I were not, in some circumstances, ready to make this sacrifice. But a sacrifice is not an increase in what is being sacrificed, namely freedom, however great the moral need or the compensation for it. Everything is what it is: liberty is liberty, not equality or fairness or justice or culture, or human happiness or a quiet conscience. (Emphasis added). Berlin's other, perhaps overarching, aim is to show how inattention to the specificity of the meanings of concepts might have potentially dangerous political repercussions. He implicitly argues that the intellectuals who promoted the idea of positive freedom as opposed to that of negative freedom contributed to the emergence of totalitarianism and fascism in Europe. (shrink)

Feed-forward Pavlovian conditioning can serve as a proximate mechanism for the evolution of social behavior. Feed-forward can provide the impetus for animals to associate other individuals' presence, and cooperation with them, with the acquisition of resources, whether or not the animals are genetically related. Other social behaviors such as play and grooming may develop as conditioned stimuli in feed-forward social systems.