| 1. |
- Falster, Daniel, et al.
(författare)
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AusTraits, a curated plant trait database for the Australian flora
- 2021
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Ingår i: Scientific Data. - : Nature Portfolio. - 2052-4463. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.
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| 2. |
- Kia, Richard, et al.
(författare)
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MicroRNA-122 : a novel hepatocyte-enriched in vitro marker of drug-induced cellular toxicity
- 2015
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Ingår i: Toxicological Sciences. - : Oxford University Press. - 1096-6080 .- 1096-0929. ; 144:1, s. 173-185
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Tidskriftsartikel (refereegranskat)abstract
- Emerging hepatic models for the study of drug-induced toxicity include pluripotent stem cell-derived hepatocyte-like cells (HLCs) and complex hepatocyte-non-parenchymal cellular coculture to mimic the complex multicellular interactions that recapitulate the niche environment in the human liver. However, a specific marker of hepatocyte perturbation, required to discriminate hepatocyte damage from non-specific cellular toxicity contributed by non-hepatocyte cell types or immature differentiated cells is currently lacking, as the cytotoxicity assays routinely used in in vitro toxicology research depend on intracellular molecules which are ubiquitously present in all eukaryotic cell types. In this study, we demonstrate that microRNA-122 (miR-122) detection in cell culture media can be used as a hepatocyte-enriched in vitro marker of drug-induced toxicity in homogeneous cultures of hepatic cells, and a cell-specific marker of toxicity of hepatic cells in heterogeneous cultures such as HLCs generated from various differentiation protocols and pluripotent stem cell lines, where conventional cytotoxicity assays using generic cellular markers may not be appropriate. We show that the sensitivity of the miR-122 cytotoxicity assay is similar to conventional assays that measure lactate dehydrogenase activity and intracellular adenosine triphosphate when applied in hepatic models with high levels of intracellular miR-122, and can be multiplexed with other assays. MiR-122 as a biomarker also has the potential to bridge results in in vitro experiments to in vivo animal models and human samples using the same assay, and to link findings from clinical studies in determining the relevance of in vitro models being developed for the study of drug-induced liver injury.
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| 3. |
- Burraco, Pablo, et al.
(författare)
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Climate change and ageing in ectotherms
- 2020
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Ingår i: Global Change Biology. - : WILEY. - 1354-1013 .- 1365-2486. ; 26:10, s. 5371-5381
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Tidskriftsartikel (refereegranskat)abstract
- Human activity is changing climatic conditions at an unprecedented rate. The impact of these changes may be especially acute on ectotherms since they have limited capacities to use metabolic heat to maintain their body temperature. An increase in temperature is likely to increase the growth rate of ectothermic animals, and may also induce thermal stress via increased exposure to heat waves. Fast growth and thermal stress are metabolically demanding, and both factors can increase oxidative damage to essential biomolecules, accelerating the rate of ageing. Here, we explore the potential impact of global warming on ectotherm ageing through its effects on reactive oxygen species production, oxidative damage, and telomere shortening, at the individual and intergenerational levels. Most evidence derives primarily from vertebrates, although the concepts are broadly applicable to invertebrates. We also discuss candidate mechanisms that could buffer ectotherms from the potentially negative consequences of climate change on ageing. Finally, we suggest some potential applications of the study of ageing mechanisms for the implementation of conservation actions. We find a clear need for more ecological, biogeographical, and evolutionary studies on the impact of global climate change on patterns of ageing rates in wild populations of ectotherms facing warming conditions. Understanding the impact of warming on animal life histories, and on ageing in particular, needs to be incorporated into the design of measures to preserve biodiversity to improve their effectiveness.
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| 4. |
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| 5. |
- Kullberg, Cecilia, 1967-
(författare)
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Behaviour under predation risk in birds
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Predation is a major selective force in the evolution of both morphological and behavioural characters in animals. The flexibility in behavioural traits according to perceived predation risk has received much attention in recent years. Since resources often are limited, prey animals face a trade-off between the risk of predation and other energy demanding activities in life. This thesis investigates the effect of predation risk on some behavioural traits in birds. The two main topics under study are predation risk and niche use in the genus Parus, and mass-dependent predation risk in birds.In a field study investigating hunting behaviour in relation to prey choice in wild pygmy owls, Glaucidium passerinum, I found that when hunting for birds, owls used a hunting strategy attacking the birds with a height advantage from ambush. This observation suggests that birds foraging high in the tree and close to the trunk, sheltered by branches, face a lower predation risk than birds foraging further out and lower down in the tree. In a laboratory experiment with wild caught willow tits, Parus montanus, I investigated the use of foraging sites in the tree according to perceived predation risk. The tits adjusted foraging behaviour to the present predation risk by choosing more sheltered foraging sites after the presentation of a model raptor. Since the hunting strategy of pygmy owls lead to selective predation of birds foraging in the outer parts of branches, the pygmy owl might acts as a keystone predator enabling coexistence of tit species that are separated in their foraging niches. The coexistence of willow tits, crested tits, Parus cristatus, and coal tits, P. ater, could be a result of a two-way asymmetric interaction between species competing for food and predator safe foraging sites.Laboratory experiments investigating take-off ability in relation to diurnal body mass increase ((8%) in wintering willow tits and great tits, Parus major, showed no measurable effect on flight ability, indicating that the small energy reserves accumulated during a day in wintering tits do not increase predation risk as a consequence of reduced take-off ability. However in a similar experiment studying migratory fuel load (up to 59% of lean body mass) in blackcaps, Sylvia atricapilla, a reduction in both velocity and angle of ascent was found suggesting that the large fuel loads needed for migration place the birds at an increased risk of predation. The study of alarmed take-off flights in great tits further suggests that great tits adjust take-off strategy to the attack trajectory of an attacking raptor, indicating that the trade-off between velocity and angle of ascent during take-off is affected by the nature of the predator attack.
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| 6. |
- Nord, Andreas, et al.
(författare)
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Avian red blood cell mitochondria produce more heat in winter than in autumn
- 2021
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Ingår i: FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - 1530-6860. ; 35:5
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Tidskriftsartikel (refereegranskat)abstract
- Endotherms in cold regions improve heat-producing capacity when preparing for winter. We know comparatively little about how this change is fueled by seasonal adaptation in cellular respiration. Thus, we studied the changes of mitochondrial function in red blood cells in sympatric Coal (Periparus ater), Blue (Cyanistes caeruleus), and Great (Parus major) tits between autumn and winter. These species differ more than twofold in body mass and in several aspects of their foraging ecology and social dominance, which could require differential seasonal adaptation of energy expenditure. Coal and Great tits in particular upregulated the mitochondrial respiration rate and mitochondrial volume in winter. This was not directed toward ATP synthesis, instead reflecting increased uncoupling of electron transport from ATP production. Because uncoupling is exothermic, this increased heat-producing capacity at the sub-cellular level in winter. This previously unexplored the route of thermogenesis in birds should be addressed in future work.
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