DataCat: The Research Data Catalogue (University of Liverpool)
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Code and input data for "Convergent evolution of body proportions in tetrapods"
No full textR code, input data and selected output examples associated with the analyses of tetrapod body proportions presented by Alice E. Maher, Karl T. Bates, Philip G. Cox, Thomas W. Maddox, Roger W.P. Kissane, Christopher Mitchell in the publication entitled "Convergent evolution of body proportions in tetrapods
Data from: Adaptive division of growth and development between hosts in helminths with two-host life cycles
No full textParasitic worms (helminths) with complex life cycles divide growth and development between successive hosts. Using data from 597 species of acanthocephalans, cestodes, and nematodes with two-host life cycles, we found that helminths with larger intermediate hosts were more likely to infect larger, endothermic definitive hosts, although some evolutionarily shifts in definitive host mass occurred without changes in intermediate host mass. Life-history theory predicts parasites to shift growth to hosts in which they can grow rapidly and/or safely. Accordingly, helminth species grew relatively less as larvae and more as adults if they infected smaller intermediate hosts and/or larger, endothermic definitive hosts. Growing larger than expected in one host, relative to host mass/endothermy, was not associated with growing less in the other host, implying a lack of cross-host tradeoffs. Rather, some helminth orders had both large larvae and large adults. Within these taxa, though, size at maturity in the definitive host was unaffected by changes to larval growth, as predicted by optimality models. Parasite life-history strategies were mostly (though not entirely) consistent with theoretical expectations, suggesting that helminths adaptively divide growth and development between the multiple hosts in their complex life cycles
Metabarcoding of canopy arthropods reveals negative impacts of forestry insecticides on community structure across multiple taxa
No full text1. Insecticides used to combat outbreaks of forest defoliators can adversely affect non-target arthropods. Forest use insecticides typically suppress Lepidoptera larvae which are the keystone of the canopy community of deciduous oak forests. The abrupt removal of this dominant component of the food web could have far-reaching implications for forest ecosystems, yet it is rarely investigated in practice owing to several methodological shortcomings. The taxonomic impediment and the biased nature of arthropod sampling techniques particularly impede the assessment of insecticide impacts on diverse communities.
2. To tackle this issue, we propose an experimental approach combining pyrethrum knockdown sampling and species determination via DNA metabarcoding, using community subsampling to derive estimates of species abundances. We applied this protocol to investigate the short-term effects of the insecticides diflubenzuron (DFB) or Bacillus thuringiensis var. kurstaki (BTK) on canopy-dwelling arthropod communities in German oak woodlands.
3. Our approach allowed us to include most of the detected diversity and integrate species abundances in our analyses. By classifying arthropod species into assemblages based on their expected sensitivity rather than coarse taxonomic groupings, we could unveil substantial effects of DFB across multiple taxa five weeks after application.
4. Although strong effects on single species appear related to direct toxicity, substantial impacts of DFB on parasitoids and xylophagous beetles suggest that anti-defoliator treatments can have previously unsuspected indirect effects on some components of forest arthropod communities. The impacts of BTK on community structure were consistent with but much weaker than that of DFB.
5. Synthesis and applications. Comparing diversity patterns in the arthropod communities of sprayed and unsprayed oak canopies, our results show that selective insecticides can alter species diversity in presumably non-sensitive taxa. Even though the ecological significance of these impacts has yet to be assessed in an operational setting, their existence calls for increased regulatory scrutiny on indirect effects. As community approaches become more attainable with the rapid development of DNA metabarcoding, we suggest the inclusion of community level endpoints as regulatory requirements for the approval of forest use insecticides
Entropy driven order in an array of nanomagnets
No full textLong-range ordering, while typically understood as a decrease in entropy, can also be driven by increasing system entropy in certain special cases. We demonstrate that artificial spin ice arrays of single-domain nanomagnets can be designed to produce entropy-driven order. We probe thermally active tetris artificial spin ice, known to have a zero point Pauli entropy, both experimentally and through simulations. We find two-dimensional magnetic ordering in one subset of the nanomagnet moments, which we demonstrate to be induced by disorder (i.e., increased entropy) in another subset of moments. Contrasting with other entropy-driven systems, the degrees of freedom in artificial spin ice are both designable and directly observable at the microscale, and the entropy of the system is precisely calculable in simulations. This robust example, in which the system’s interactions and ground state entropy are well-defined, significantly expands the experimental landscape for the study of entropy-driven ordering
Plastic responses of survival and fertility following heat stress in pupal and adult Drosophila virilis
No full textThe impact of rising global temperatures on survival and reproduction is putting many species at risk of extinction. In particular, it has recently been shown that thermal effects on reproduction, particularly limits to male fertility, can underpin species distributions in insects. However, the physiological factors influencing fertility at high temperatures are poorly understood. Key factors that affect somatic thermal tolerance such as hardening, the ability to phenotypically increase thermal tolerance after a mild heat shock, and the differential impact of temperature on different life stages, are largely unexplored for thermal fertility tolerance. Here, we examine the impact of high temperatures on male fertility in the cosmopolitan fruit fly Drosophila virilis. We first determined whether temperature stress at either the pupal or adult life-history stage impacts fertility. We then tested the capacity for heat-hardening to mitigate heat-induced sterility. We found that thermal stress reduces fertility in different ways in pupae and adults. Pupal heat stress delays sexual maturity, whereas males heated as adults can reproduce initially following heat stress, but lose the ability to produce offspring. We also found evidence that while heat-hardening in D. virilis can improve high temperature survival, there is no significant protective impact of this same hardening treatment on fertility. These results suggest that males may be unable to prevent the costs of high temperature stress on fertility through heat-hardening which limits a species’ ability to quickly and effectively reduce fertility loss in the face of short-term high temperature events
Data for: Termites have wider thermal limits to cope with environmental conditions in savannas
No full textThe most diverse and abundant family of termites, the Termitidae, evolved in African tropical forests. They have since colonised grassy biomes such as savannas. These open environments have more extreme conditions than tropical forests, notably wider extremes of temperature and lower precipitation levels and greater temporal fluctuations (both annual and diurnal variation). These conditions are challenging for soft-bodied ectotherms, such as termites, to survive in, let alone become as ecologically dominant as termites have.
Here, we quantified termite thermal limits to test the hypothesis that these physiological limits have widened in savanna termite species to facilitate their existence in savanna environments.
We sampled termites directly from mound structures, across an environmental gradient in Ghana, ranging from wet tropical forest through to savanna. At each location we quantified both Critical Thermal Maximum (CT max) and Critical Thermal Minimum (CTmin) of all the most abundant mound-building Termitidae species in the study areas. We modelled the thermal limits in two separate mixed effects models against: canopy cover at the mound, temperature and rainfall, as fixed effects, with sampling location as a random intercept.
For both CTmax and CTmin savanna species had significantly more extreme thermal limits than forest species. Between and within environments, areas with higher amounts of canopy cover were significantly associated with lower CTmax values of the termite colonies. CTmin was significantly positively correlated with rainfall. Temperature was retained in both models, however it did not have a significant relationship in either. Sampling location explained a large proportion of the residual variation, suggesting there are other environmental factors that could influence termite thermal limits.
Our results suggest there has been a widening of the thermal limits in termite savanna species. These physiological differences, in conjunction with other behavioural adaptations, are likely to have enabled termites to cope with the more extreme environmental conditions found in savanna environments and facilitated their expansion into open tropical environments
Data from: Biodiversity and yield trade-offs for organic farming
No full textOrganic farming supports higher biodiversity than conventional farming, but at the cost of lower yields. We conducted a meta-analysis quantifying the trade-off between biodiversity and yield, comparing conventional and organic farming. We developed a compatibility index to assess whether biodiversity gains from organic farming exceed yield losses, and a substitution index to assess whether organic farming would increase biodiversity in an area if maintaining total production under organic farming would require cultivating more land at the expense of nature. Overall, organic farming had 23% gain in biodiversity with a similar cost of yield decline. Biodiversity gain is negatively correlated to yield loss for microbes and plants, but no correlation was found for other taxa. The biodiversity and yield trade-off varies under different contexts of organic farming. The overall compatibility index value was close to zero, with negative values for cereal crops, positive for non-cereal crops, and varies across taxa. Our results indicate that, on average, the proportion of biodiversity gain is similar to the proportion of yield loss for paired field studies. For some taxa in non-cereal crops, switching to organic farming can lead to a biodiversity gain without yield loss. We calculated the overall value of substitution index and further discussed the application of this index to evaluate when the biodiversity of less intensified farming system is advantageous
Drosophila pseudoobscura
No full textA photography collection (lateral, ventral, and dorsal images) of Drosophila pseudoobscura. Part of a collection of photographs at Drosophoto.co
Supplementary material: "Real-time monitoring of dynamics and interactions of bacteria and the early-stage formation of biofilms"
No full textThis supporting material consists of a series of videos showing the motion and interaction with surfaces of Escherichia coli bacteria over time. The frame rate of each video is 5x the original acquisition frame rate. The working concentration of Escheria coli bacteria used is 108 CFU/mL. Each test was conducted at 37 °C exposing the bacteria to control glass surface or to glass surface treated with BKC following the procedure described in the materials and methods section of the manuscript
Decolonial Research Methods: Resisting Coloniality in Academic Knowledge Production (webinar series)
Get PDFThese files are the transcripts of talks that were given in a webinar series about decolonial research methods and methodologies. The webinars took place between October 2021 and December 2021.
The talks were given by:
Prof Vineeta Sinha (National University of Singapore)
Prof Linda T. Smith (Te Whare Wānanga o Awanuiārangi)
Prof Raewyn Connell (University of Sydney)
Prof Walter Mignolo (Duke University)
Prof Sujata Patel (Umeå University)
Prof Jeong-Eun Rhee (Long Island University, Post)
The talks were transcribed by:
Ms Yuqi Ong
Ms Intan Syazwani
The webinar series was organised by:
Dr Leon Moosavi (University of Liverpool)
The webinar series was funded by:
The National Centre for Research Methods (UK
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