Deuteron Dipole Polarizabilities and Sum Rules

The scalar, vector, and tensor components of the (generalized) deuteron electric polarizability are calculated, as well as their logarithmic modifications. Several of these quantities arise in the treatment of the nuclear corrections to the deuterium Lamb shift and the deuterium hyperfine structure. A variety of second-generation potential models are used and a (subjective) error is assigned to the calculations. The zero-range approximation is used to analyze a subset of the results, and a simple relativistic version of this approximation is developed.Comment: 14 pages, LaTex - submitted to Physical Review

The nucleon-sigma coupling constant in QCD Sum Rules

The external-field QCD Sum Rules method is used to evaluate the coupling constant of the light isoscalar-scalar meson (``$\sigma$'' or \epsilon) to the nucleon. The contributions that come from the excited nucleon states and the response of the continuum threshold to the external field are calculated. The obtained value of the coupling constant is compatible with the large value required in one-boson exchange potential models of the two-nucleon interaction.Comment: 11 pages, 4 figure

Discrepancy between otolith and tag-recovery estimates of growth for two South African surf-zone teleost species

Growth rates determined from recovered tagged galjoen Dichistius capensis and white steenbras Lithognathus lithognathus were compared to predictions from growth models based on otolith ring counts. Galjoen could notbe sexed externally, but it was assumed that all fish >450 mm total length were females, which grow faster than males. Those smaller than this were assumed to include mostly males and were treated as a “male” sample. Maleand female white steenbras grow equivalently. Tagged “male” (n = 322), and female galjoen (n = 34) and white steenbras (n = 14) grew more slowly than the model predictions. The discrepancy is likely attributable to the physiological effect of external tags on growth

Use of blood lactate concentration as a marker of training status

The recent development of portable blood lactate analysers has made it relatively easy to test blood lactate concentration in the field. This paper discusses the validity and accuracy of measuring blood lactate concentration as a marker of training status or exercise intensity and examines the assumptions upon which the above practice is based. The mechanisms responsible for blood lactate accumulation according to different theories are discussed, followed by a review of the literature regarding the measurement, tracking and interpretation of blood lactate concentration. The use of blood lactate concentration to monitor either training status or intensity is complicated by the inaccuracy of portable lactate analysers, multiple confounding factors affecting blood lactate concentration such as carbohydrate depletion, mode of exercise, ambient temperature, muscle damage and overtraining and difficulty in interpreting the results. The relationship between changes in blood lactate concentration following training and subsequent performance in competition has not been convincingly established. Therefore it may be concluded that changes in blood lactate concentration should be interpreted with caution as the changes do not track training status or exercise intensity with sufficient precision to have a practical application

Lecturer conceptions of and approaches to decolonisation of curricula

This report forms part of a larger project that investigated lecturer and student conceptions of decolonisation and decolonisation of curricula at subject level in a South African higher education institution. The study adopted an interpretive paradigm and an on-line questionnaire was administered to all the lecturers in a Faculty of Education in the Western Cape. A de-colonial perspective was used as a lens to interpret the data. In general, participants viewed decolonisation as a worthwhile project that can contribute to the development of a socially-just post-colonial and post-apartheid society. Consistent with the fact that knowledge is created differently in different subjects, the findings revealed varied conceptions of and approaches to the decolonisation of curricula among academics. The study concludes that decolonisation is a complex and multi-layered concept. However. if there are shared understandings of what decolonisation of curricula entails in the different disciplines, and consultative, participatory multi-disciplinary/trans-disciplinary approaches to decolonisation are adopted, significant progress will be made in achieving the goal of decolonising university curricula

An interacting quark-diquark model of baryons

A simple quark-diquark model of baryons with direct and exchange interactions is constructed. Spectrum and form factors are calculated and compared with experimental data. Advantages and disadvantages of the model are discussed.Comment: 13 pages, 3 eps-figures, accepted by Phys.Rev. C Rapid Communication

The Learnability of the Wh-Island Constraint in Dutch by a Long Short-Term Memory Network

The current study investigates whether a Long Short-Term Memory (LSTM) network can learn the wh-island constraint in Dutch in a way comparable to human native speakers. After establishing with an acceptability judgement task that native speakers demonstrate a clear sensitivity to wh-island violations, the LSTM network was tested on the same sentences. Contrary to the results of the native speakers, the network was not able to recognize wh-islands and to block gap expectancies within them. This suggests that input and the network’s inductive biases alone might not be enough to learn about syntactic island constraints, and that built-in language knowledge or abilities might be necessary