A robustness approach to theory building: A case study of language evolution

Models of cognitive processes often include simplifications, idealisations, and fictionalisations, so how should we learn about cognitive processes from such models? Particularly in cognitive science, when many features of the target system are unknown, it is not always clear which simplifications, idealisations, and so on, are appropriate for a research question, and which are highly misleading. Here we use a case-study from studies of language evolution, and ideas from philosophy of science, to illustrate a robustness approach to learning from models. Robust properties are those that arise across a range of models, simulations and experiments, and can be used to identify key causal structures in the models, and the phenomenon, under investigation. For example, in studies of language evolution, the emergence of compositional structure is a robust property across models, simulations and experiments of cultural transmission, but only under pressures for learnability and expressivity. This arguably illustrates the principles underlying real cases of language evolution. We provide an outline of the robustness approach, including its limitations, and suggest that this methodology can be productively used throughout cognitive science. Perhaps of most importance, it suggests that different modelling frameworks should be used as tools to identify the abstract properties of a system, rather than being definitive expressions of theories

Regolith production and transport at the Susquehanna Shale Hills Critical Zone Observatory, Part 2: Insights from meteoric 10Be

Regolith-mantled hillslopes are ubiquitous features of most temperate landscapes, and their morphology reflects the climatically, biologically, and tectonically mediated interplay between regolith production and downslope transport. Despite intensive research, few studies have quantified both of these mass fluxes in the same field site. Here we present an analysis of 87 meteoric 10Be measurements from regolith and bedrock within the Susquehanna Shale Hills Critical Zone Observatory (SSHO), in central Pennsylvania. Meteoric 10Be concentrations in bulk regolith samples (n=73) decrease with regolith depth. Comparison of hillslope meteoric 10Be inventories with analyses of rock chip samples (n=14) from a 24 m bedrock core confirms that >80% of the total inventory is retained in the regolith. The systematic downslope increase of meteoric 10Be inventories observed at SSHO is consistent with 10Be accumulation in slowly creeping regolith (∼ 0.2 cm yr-1). Regolith flux inferred from meteoric 10Be varies linearly with topographic gradient (determined from high-resolution light detection and ranging-based topography) along the upper portions of hillslopes at SSHO. However, regolith flux appears to depend on the product of gradient and regolith depth where regolith is thick, near the base of hillslopes. Meteoric 10Be inventories at the north and south ridgetops indicate minimum regolith residence times of 10.5 ± 3.7 and 9.1 ± 2.9 ky, respectively, similar to residence times inferred from U-series isotopes in Ma et al. (2013). The combination of our results with U-series-derived regolith production rates implies that regolith production and erosion rates are similar to within a factor of two on SSHO hillcrests. ©2013. American Geophysical Union. All Rights Reserved

Living with vulval lichen sclerosus: a systematic review

Lichen sclerosus (LS) is an under‐researched disorder, particularly from the perspective of individuals who have the condition. A recent James Lind Alliance Priority Setting Partnership identified uncertainties in many aspects of the condition, including its impact on quality of life which was ranked within the ‘Top 10’ future research priorities.1,2 We set out to systematically review the qualitative literature exploring the lived experience of vulval LS (for the full protocol see PROSPERO ID:CRD42018106947)

In-flight measurement of ice growth on an airfoil using an array of ultrasonic transducers

Results of preliminary tests to measure ice growth on an airfoil during flight icing conditions are presented. Ultrasonic pulse echo measurements of ice thickness are obtained from an array of eight ultrasonic transducers mounted flush with the leading edge of the airfoil. These thickness measurements are used to document the evolution of the ice shape during the encounter in the form of successive ice profiles. Results from 3 research flights are presented and discussed. The accuracy of the ultrasonic measurements is found to be within 0.5 mm of mechanical and stereo photograph measurements of the ice accretion

VIII.—Notes on Forficulidæ, with descriptions of new species in the collection of the Natural History Museum, South Kensington

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Dissociative Autoionization in (1+2)-photon Above Threshold Excitation of H2 Molecules

We have theoretically studied the effect of dissociative autoionization on the photoelectron energy spectrum in (1+2)-photon above threshold ionization(ATI) of H2 molecules. We have considered excitation from the ground state X-singlet-Sigma-g+(v=0,j) to the doubly excited autoionizing states of singlet-Sigma-u+ and singlet-Pi-u+ symmetry, via the intermediate resonant B-singlet-Sigma-u+(v=5,j) states. We have shown that the photoelectron energy spectrum is oscillatory in nature and shows three distinct peaks above the photoelectron energy 0.7 eV. This feature has been observed in a recent experiment by Rottke et al, J. Phys. B, Vol. 30, p-4049 (1997).Comment: 11 pages and 4 figure

Relation of the barberry to stem rust in Iowa

It has been definitely known since 1865 that the European barberry is the alternate host of stem rust (Puccinia graminis); yet the exact relation of this shrub to the annual appearance of stem rust of our grains and grasses is not well understood. Tulasne brothers (18) (1847), de Bary (1) (1865) and others rarely described and figured the morphology of teleutosporic germination. They gave little consideration, however, to the questions as to what environmental conditions influence such germination and the production, dissemination, viability and growth of the sporidia—conditions that have a fundamental bearing on serious attacks of stem rust

Antecedents of Infant Mortality: An Analysis of Risk Factors in Rural and Urban Arkansas

This research examines the relationship between social and biological characteristics of the infant and mother and the probability of infant survival through the first year of life. The research also includes a consideration of the influence of residence (rural vs. urban). Employing linked birth and death certificate data for Arkansas (1985-1989), a logit model was estimated to assess the impact of social and biological factors on the probability of survival. The results indicate that metropolitan residence is positively associated with infant survival, but only at a marginal significance level. Other notable results include the importance of prenatal care and a lack of significance of race when other factors are controlled