A psychology of the in between?

The authors offer a theory of agency that is general enough to apply to whole organisms and single cells, and meaningful enough to highlight problems that embodied cognition theory has overlooked. The authors insist that the interesting thing about minds is what goes on in between activities; this leaves unclear what a specifically enactivist empirical program could look like. But the book can be read as a contribution to a broader project of instituting a full-blown post-cognitivist science of the mind

Book Review: Evolving Enactivism: Basic Minds Meet Content

Cornet part for music intended to accompany a silent film

Plant exudates improve the mechanical conditions for root penetration through compacted soils

ACKNOWLEDGEMENTS Funding for this project was provided by Tertiary Education Trust Funds (TETFund) and Ambrose Alli University. We wish to thank Annette Raffan for technical support. M. Naveed is funded by the Biotechnology and Biological Sciences Research Council (BBSRC) project ‘Rhizosphere by Design’ (BB/L026058/1). Open access via Springer Compact AgreementPeer reviewedPublisher PD

Radical embodiment in two directions

Radical embodied cognitive science is split into two camps: the ecological approach and the enactive approach. We propose that these two approaches can be brought together into a productive synthesis. The key is to recognize that the two approaches are pursuing different but complementary types of explanation. Both approaches seek to explain behavior in terms of the animal–environment relation, but they start at opposite ends. Ecological psychologists pursue an ontological strategy. They begin by describing the habitat of the species, and use this to explain how action possibilities are constrained for individual actors. Enactivists, meanwhile, pursue an epistemic strategy: start by characterizing the exploratory, self-regulating behavior of the individual organism, and use this to understand how that organism brings forth its animal-specific umwelt. Both types of explanation are necessary: the ontological strategy explains how structure in the environment constrains how the world can appear to an individual, while the epistemic strategy explains how the world can appear differently to different members of the same species, relative to their skills, abilities, and histories. Making the distinction between species habitat and animal-specific umwelt allows us to understand the environment in realist terms while acknowledging that individual living organisms are phenomenal beings

An Analysis of the Parasites of a Mid-winter Population of the Snowshoe Hare, Lepus americanus, on Insular Newfoundland During a Cyclical Peak

A mid-winter sample of 78 Snowshoe Hares (Lepus americanus) was collected during their cyclical peak in population from three eco-regions (Western Newfoundland, North Shore and Avalon Forest) on insular Newfoundland and was examined for the presence of enteric parasites. The length of the hares was significantly shorter in the Avalon Forest Region (n = 27) than those of the Western Newfoundland Region (n = 25) and North Shore Region (n = 26) samples (P ≤ 0.001 and P ≤ 0.003 respectively); however, no significant differences occurred for other morphological measurements. Four species of parasites, two cestodes (Mosgovoyia pectinata and Taenia pisiformis) and two nematodes (Obeliscoides cuniculi and Rauschia triangularis), were recovered. Taenia pisiformis was recovered from the North Shore eco-region only. No other significant differences with respect to their prevalence, intensity, mean intensity, relative density and dispersion between eco-regions were found. Within eco-regions, only R. triangularis showed a significantly higher value (P ≤ 0.027) for males and the prevalence of this species was lower than that previously reported. The occurrence of O. cuniculi was significantly different between the higher weight classes of hares and the prevalence of this species was higher than that previously reported. No trends for multiple infections were noted. The expansion of a new animal species, the Coyote, Canis latrans, to Newfoundland appeared to have had no effect on the diversity of parasites found in the hare

Interactive effects of low molecular weight carbon compounds on N2O emissions

Low molecular weight carbon (C) compounds in hotspots such as the rhizosphere can greatly affect nitrate reduction processes. Towards a better prediction of N2O emission from denitrification, we are still lacking understanding of responses to the supply of complex C compound mixtures such as rhizodeposits versus the often examined response to individually amended C compounds. In a laboratory study, we applied three C compounds, glucose, citric acid and glutamic acid, individually or as a three-compound mixture to 14NH415NO3 amended soil at 80% water-filled pore space. For the individual C compound treatments, the substrateswere enriched in 13C-C. The mixture was enriched in 13C-C either in all constituent compounds or in one of the compounds only, resulting in four different treatments. This set-up enabled quantification of the utilization of each compound for heterotrophic respiration when applied individually and in combination, and for this to be related to the dynamics of 15N-NO3- reduction to 15N-N2O. The total 15N-N2O emission from the compound mixture over 10 days was similar to the total emission predicted from the average of the individual compound treatments This could suggest potential predictability of denitrification responses to complex mixtures of C based on knowledge of its constituents. However, immediate and simultaneous peaks of 15N-N2O and 13C-CO2 fluxes from the compound mixture contrasted with observed delays in 15N-N2O and 13C-CO2 fluxes when the compounds had been applied individually. Moreover, relative contributions of the C compounds to 13C-CO2 respiration from the compound mixture were different from the predicted contributions based on their individual application. While contributions of glutamic acid-C and citric acid-C to respiration in mixture during peak 15N-N2O emission were increased, glucose utilization in the mixture treatment was significantly lower. These findings give a glimpse of the challenges we are facing when trying to predict nitrate reduction occurring in the rhizosphere where interactions between C compounds and the soil matrix, as well as within the wider heterotrophic community, determine process rates. Given that most of our understanding of the role of C in regulating nitrate reduction, is informed from single compound studies, we require more evidence on the effects and innate interactions of compound mixtures to be able to predict responses to C sources

Smith, K.A., Ball, T., Conen, F., Dobbie, K.E., Massheder, J. & Rey, A. 2003. Exchange of greenhouse gases between soil and atmosphere: interactions of soil physical factors and biological processes. European Journal of Soil Science, 54, 779–791.

Commentary on the impact of Smith et al. (2003) by G. Guggenberger, B. Ludwig and M. Meno

Closing maize yield gaps in sub-Saharan Africa will boost soil N2_{2}O emissions

In sub-Saharan Africa (SSA), the most important staple crop is maize; the production of which is dominated by smallholder farming systems using low external inputs (<10 kg N ha$^{−1}$) resulting in low crop yields and large yield gaps (difference between actual and potential yields). To assess increases in soil N$_{2}$O emissions when closing maize yield gaps by increased fertilizer use, we reviewed the literature, developed a relationship between yield gaps and soil N$_{2}$O emissions, and used it to scale across SSA. According to our analysis, N$_{2}$O emissions from maize production will increase from currently 255 to 1755 ± 226 Gg N$_{2}$O-N year$^{−1}$ (+589%) if existing maize yield gaps are closed by 75%, increasing total anthropogenic N$_{2}$O emissions for SSA by c. 50%