Acquisition of behavioral control by static visual features of an imprinting object: Species generality

Previous work had indicated that after prolonged exposure to a moving object, ducklings will direct filial responses toward that object even if it remains stationary during its presentation. The present experiment demonstrated the wide species generality of this effect by obtaining similar results in newly hatched chickens, pheasant, turkeys, and quail, as well as ducks.     

Simulations in distance education: Progress towards an evaluation instrument

This article reports on a study in which an interactive computer‐based learning resource consisting of a tutorial with a decision support system and simulations, is evaluated in the context of a distance education business degree course. The primary purpose of the study was to develop and test an instrument for evaluation of the learning resource, with particular reference to simulations. The instrument adds further dimensions to factors such as learner support and engagement, to incorporate elements of motivation and transfer. Consequently, the scales that comprise the instrument include three key areas: features of the computer package, the effect on students” motivation, and the impact on their ability to transfer knowledge to the workplace. As a result of the analysis, a reliable and valid evaluation instrument that includes components of these three areas is provided. It is expected that other researchers will be able to develop and refine this instrument to evaluate various forms of computer‐based educational resources.     

The effect of electron attachment on the ion mobility curves in the Zeleny air blast method of ion mobility measurement

In a recent paper Professor John Zeleny published curves obtained for ion mobilities at different ion ages in relatively pure N₂ using his classical air blast method. Two features are of especial interest; one the apparent gradual displacement of the negative ion peak to lower mobilities as the ion age increases and the other a marked asymmetry of the electron peak on the low mobility side. This Zeleny interprets as an unresolved negative ion mobility of value about 100 cm./sec. per volt/cm. Such a mobility can only be explained by a carrier that is ion part of its life and electron part of its life, the electronic and ionic phases alternating frequently. The writers indicate that the latter interpretation cannot be correct on the basis of the energies and probabilities involved in electron attachment. Analysis shows that the whole series of the observed phenomena in N₂ by this method are successfully accounted for on the proper application of the simplified theory of electron attachment to the air blast method. Since the attachment phenomena have to date not been applied to this type of mobility study it was felt of importance to present this analysis in order to guide future investigations by this method.     

The theory of recombination of gaseous ions

The bearing of the recent results of Marshall on the theory of recombination of gaseous ions is discussed. It is shown, by solution of the Brownian movement equation for two ions of opposite sign, in a gas, that the average relative displacement in a time π is little influenced by the attractive forces, except for distances of the order of magnitude of 10^?5 cm. or less, at ordinary temperatures. This conclusion, that in general the motion of the ions relative to each other is largely one of random diffusion, is in good agreement with the interpretation forced by Marshall's study of the variation of the coefficient of recombination α with time and concentration of ions. This also indicates that the theoretical approach of Langevin to the solution of the recombination problem is untenable, while that of Thomson is justified. The theory, of Thomson is discussed and, is compared with observation. It appears to fit qualitatively as accurately as the facts are known.It is then shown how the success of any theoretical treatment is limited due to our ignorance of the nature of the mass of the ion, a condition which, however, enables us to understand the very small range of variation of α among the different gases.     

Single‐sex schooling and labour market outcomes

One quarter of the 1958 British Birth cohort attended single‐sex secondary schools. This paper asks whether sex‐segregated schooling had any impact on the experience of gender differences in the labour market in mid‐life. We examine outcomes at age 42, allowing for socio‐economic origins and abilities measured in childhood. We find no net impact of single‐sex schooling on the chances of being employed in 2000, nor on the horizontal or social class segregation of mid‐life occupations. But we do find a positive premium (5%) on the wages of women (but not men), of having attended a single‐sex school. This was accounted for by the relatively good performance of girls‐only school students in post‐16 qualifications, not by the wider range of subjects studied by both girls and boys at single‐sex schools. Men’s labour market attainments were more closely related to attending private schools and to parental class, suggesting that the intergenerational transmission of advantage, while not related to coeducation, is related to gender.     

The militant‐moderate agitator: Daniel O'Connell and catholic emancipation in Ireland

An analysis of O'Connell's campaign for Catholic civil rights in the early nineteenth century demonstrates the use of antithetical, militant‐moderate, agitational strategies. By provocation and coercion he induced Parliament to accede to Catholic demands, while at the same time he controlled his turbulent followers with moderate strategies. O'Connell's rhetorical choices were effective because 1) he personified Irish needs and attitudes, and 2) his militancy coincided with English images of Irish disloyalty.