Building Collaborative Capacities in Learners: The M/cyclopedia Project Revisited

In this paper we trace the evolution of a project using a wiki-based learning environment in a tertiary education setting. The project has the pedagogical goal of building learners’ capacities to work effectively in the networked, collaborative, creative environments of the knowledge economy. The paper explores the four key characteristics of a ‘produsage’ environment and identifies four strategic capacities that need to be developed in learners to be effective ‘produsers’ (user-producers). A case study is presented of our experiences with the subject New Media Technologies, run at Queensland University of Technology, Brisbane, Australia. This progress report updates our observations made at the 2005 WikiSym conference

Post-dropping behavior of potato aphids (Macrosiphum euphorbiae)

Funding: Perry Foundation, University of St Andrews, Scottish Government Rural and Environmental Sciences and Analytical Services Division.Dropping behavior is an effective antipredator defense utilized by many insects including aphids, which drop from plants to lower plant parts or underlying substrates to avoid attack from predatory invertebrates. While research commonly focusses on triggers of dropping, less attention is given to what happens to prey individuals following escape drops. In this study, the duration of tonic immobility, recovery rates, and cases of “instant recovery” (re-clinging to lower plant parts) exhibited by potato aphids (Macrosiphum euphorbiae) that dropped from potted seedlings in response to introduced ladybird (Adalia bipunctata) adults, lacewing (Chrysoperla carnea) larvae, and a standardized tactile stimulus were investigated in relation to a range of environmental factors. Air temperature had a negative correlation with the duration of post-dropping tonic immobility; as temperature increased, time spent motionless decreased. Aphids also showed a pattern of increased recovery rate at higher temperatures. Aphids may be selected to move off the substrate quicker to avoid risks of overheating/desiccation at higher temperatures; and/or higher body temperature facilitates locomotion. Stimulus type also influenced recovery rate back to the original seedling, with aphids generally recovering after the standardized stimulus quicker than after dropping triggered by a real predator. Considering cases of instant recovery onto lower-reaches of the host seedling, seedling height influenced the likelihood of re-clinging, with aphids that managed to instantly recover dropping from, on average, taller seedlings than aphids that dropped to the substrate. Plant architecture could mitigate the costs of dropping for aphids, but further studies quantifying understory foliage cover are needed.Publisher PDFPeer reviewe

Influence of Hamiltonella defensa infection and predator type on anti-predator behaviours in pea (Acyrthosiphon pisum) and potato aphids (Macrosiphum euphorbiae)

Funding: RKH thanks the Perry Foundation and the University of St Andrews for funding. AJK is supported by the strategic research program funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division.Facultative endosymbionts can induce benefits and costs to their aphid hosts. In the pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae), infection with the γ-proteobacterium Hamiltonella defensa Moran et al. can confer resistance against parasitoids, but may also reduce the frequency of aggressive and escape behaviours exhibited in response to predators. In potato aphids, Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae), H. defensa does not appear to influence susceptibility to parasitism, but its impact on anti-predator behaviours remains unexplored. Here we investigated defensive behaviours in two pea aphid lines (differing in H. defensa-infection status) and four potato aphid lines (that additionally differed in genotype-associated parasitism susceptibility) when faced with foraging ladybirds – Adalia bipunctata (L.) (Coleoptera: Coccinellidae) – and lacewings Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae). In response to ladybirds, symbiont-infected pea aphids exhibited proportionately fewer evasive defences (dropping and walking away) than non-infected (cured) pea aphids, but more frequent aggressive kicking. Ladybirds provoked more evasive, aggressive, and total defensive behaviours than lacewings. For potato aphids, symbiont status, predator type, and aphid genotype (i.e., assumed parasitism susceptibility) all influenced behavioural repertoires. Overall, infected lines showed greater differentiation in behaviours in response to the two predators than the uninfected lines. The presence of the symbiont H. defensa may be a key determinant of aphid anti-predator behaviours, but the fitness consequences of this are unresolved. In our study, neither symbiont infection status nor aphid genotype affected the number of aphids consumed by predators.Publisher PDFPeer reviewe

Drop when the stakes are high : adaptive, flexible use of dropping behaviour by aphids

RKH was funded by the Perry Foundation and the University of St Andrews. AJK is supported by the strategic research programme funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division.For herbivorous insects, dropping from the host plant is a commonly-observed antipredator defence. The use of dropping compared to other behaviours and its timing in relation to contact with a predator was explored in both pea aphids (Acyrthosiphon pisum) and potato aphids (Macrosiphum euphorbiae). Pea aphids dropped more frequently in response to ladybird adults (Adalia bipunctata) than lacewing larvae (Chrysoperla carnea). Potato aphids mainly walked away or backed-up in response to both predator types; but they dropped more frequently relative to other non-walking defences when faced with ladybird adults. Contact with a predator was an important influencer of dropping for both species, and most drops occurred from adjacent to the predator. Dropping appears to be a defence adaptively deployed only when the risk of imminent predation is high; factors that increase dropping likelihood include presence of faster-foraging predators such as adult ladybirds, predator proximity, and contact between aphid and predator.Publisher PDFPeer reviewe

Elucidating stygofaunal trophic web interactions via isotopic ecology

© 2019 Saccò et al. Subterranean ecosystems host highly adapted aquatic invertebrate biota which play a key role in sustaining groundwater ecological functioning and hydrological dynamics. However, functional biodiversity studies in groundwater environments, the main source of unfrozen freshwater on Earth, are scarce, probably due to the cryptic nature of the systems. To address this, we investigate groundwater trophic ecology via stable isotope analysis, employing δ13C and δ15N in bulk tissues, and amino acids. Specimens were collected from a shallow calcrete aquifer in the arid Yilgarn region of Western Australia: a well-known hotspot for stygofaunal biodiversity. Sampling campaigns were carried out during dry (low rainfall: LR) and the wet (high rainfall: HR) periods. δ13C values indicate that most of the stygofauna shifted towards more 13C-depleted carbon sources under HR, suggesting a preference for fresher organic matter. Conversion of δ15N values in glutamic acid and phenylalanine to a trophic index showed broadly stable trophic levels with organisms clustering as low-level secondary consumers. However, mixing models indicate that HR conditions trigger changes in dietary preferences, with increasing predation of amphipods by beetle larvae. Overall, stygofauna showed a tendency towards opportunistic and omnivorous habits- typical of an ecologically tolerant community-shaped by bottom-up controls linked with changes in carbon flows. This study provides baseline biochemical and ecological data for stygofaunal trophic interactions in calcretes. Further studies on the carbon inputs and taxaspecific physiology will help refine the interpretation of the energy flows shaping biodiversity in groundwaters. This will aid understanding of groundwater ecosystem functioning and allow modelling of the impact of future climate change factors such as aridification

Gambling harm and crime careers

Incarcerated populations across the world have been found to be consistently and significantly more vulnerable to problem gambling than general populations in the same countries. In an effort to gain a more specific understanding of this vulnerability the present study applied latent class analysis and criminal career theory to gambling data collected from a sample of English and Scottish, male and female prisoners (N=1057). The analysis found six clusters measured by responses to the Problem Gambling Severity Index (PGSI), primarily distinguished by loss chasing behaviour. Longitudinal offending data drawn from the Police National Computer database found four criminal career types, distinguished by frequency and persistence over time. A significant association was found between higher level loss chasing and high rate offending in criminal careers. High rate offenders whose offending peaked in their mid 20’s were 5.3 times more likely to be higher level loss chasers and high rate chronic persistent offenders 3.7 times more likely than other criminal career types. Theories that link gambling, offending and impulse control are discussed and targeted interventions are proposed

A route to decreasing N pollution from livestock:Use of Festulolium hybrids improves efficiency of N flows in rumen simulation fermenters

Ruminant agriculture suffers from inefficient capture of forage protein and consequential release of N pollutants to land. This is due to proteolysis in the rumen catalyzed by both microbial but initially endogenous plant proteases. Plant breeding-based solutions are sought to minimize these negative environmental impacts. The aim of this study was to perform an integrated study of rumen N metabolism using semi-continuous rumen simulation fermenters (Rusitec) to explore the extent to which swards containing Festulolium populations (interspecific hybrids between Lolium and Festuca grass species) with decreased rates of endogenous protein degradation conferred advantageous protein utilization in comparison with a National Listed perennial ryegrass. An in vitro experiment was conducted using three Festulolium hybrids (Lolium perenne × Festuca arundinacea var. glaucescens, LpFg; Lolium perenne × Festuca mairei, LpFm; and Lolium multiflorum × Festuca arundinacea var. glaucescens, LmFg) and a Lolium perenne, Lp control. LpFm and LmFg demonstrated significantly lower plant-mediated proteolysis than the control. Fresh forage was incubated in Rusitec with rumen fluid from four donor cows. Feed disappearance and production of gas, methane, and volatile fatty acids were similar across cultivars. Whereas no differences in microbial protein synthesis were noted across treatments during early fermentation (0–6 hr after feeding), an increased microbial N flow in LpFm (+30%) and LmFg hybrids (+41%) was observed during late fermentation (6–24 hr after feeding), with higher overall microbial N flows (+13.5% and + 20.2%, respectively) compared with the control (Lp). We propose an underpinning mechanism involving the partitioning of amino acid catabolism toward branched-chain amino acids and microbial protein synthesis in grasses with slow plant-mediated proteolysis instead of accumulation of rumen ammonia in grasses with fast plant-mediated proteolysis. These observations indicate the potential of Festulolium hybrids with a slow plant-mediated proteolysis trait to improve the efficiency of capture of forage protein and decrease the release of N pollutants onto the land.The authors thank the field work staff for growth and maintenance of field plots of the grass material, the staff at Trawsgoed “D‐unit” for provision of rumen fluid, Delma Jones and the staff of Analytical Chemistry for forage quality analysis, Susan Girdwood for VFA analysis, and Debbie Allen for 15N analyses. This work was funded by BBSRC (BBS/E/W/10964; BBS/E/W/0012843D) and Aberystwyth University (SK). Biotechnology and Biological Sciences Research Council. Grant Numbers: BBS/E/W/0012843D, BBS/E/W/1096