153 research outputs found
Complete Genome Sequence of Stenotrophomonas maltophilia Strain CF13, Recovered from Sputum from an Australian Cystic Fibrosis Patient.
Stenotrophomonas maltophilia isolate CF13 is a multidrug-resistant isolate that was recovered in Sydney, Australia, in 2011, from a sputum sample from an individual with cystic fibrosis. The genome sequence of CF13 was completed using long- and short-read technologies
Epigenetic change induced by in utero dietary challenge provokes phenotypic variability across multiple generations of mice
Transmission of epigenetic information between generations occurs in nematodes, flies and plants, mediated by specialised small RNA pathways, histone H3K9me3, H3K27me3, H4K16ac and DNA methylation 1-3 . In higher vertebrates, epidemiological and experimental evidence supports similar trans-generational effects 4,5 although the mechanisms that underpin these are incompletely understood 6-9 . We generated a luciferase reporter knock-in mouse for the imprinted Dlk1 locus, to visualise and track epigenetic fidelity across generations. We showed that exposure to high-fat diet (HFD) in pregnancy provokes sustained re-expression of the normally silent maternal Dlk1 allele in offspring, coincident with increased DNA methylation at the Dlk1 sDMR . Interestingly, maternal Dlk1 mis-expression was also evident in the next generation (F2), exclusively in animals derived from F1-exposed females. Oocytes from these females showed altered microRNA and gene expression, without any major changes in underlying DNA methylation, and correctly imprinted Dlk1 expression resumed in subsequent generations (F3 onwards). Our results reveal how canonical and non-canonical imprinting mechanisms enable the foetal epigenome to adapt to in utero challenge to modulate the properties of two successive generations of offspring
Evolution of self-organized division of labor in a response threshold model
Division of labor in social insects is determinant to their ecological success. Recent models emphasize that division of labor is an emergent property of the interactions among nestmates obeying to simple behavioral rules. However, the role of evolution in shaping these rules has been largely neglected. Here, we investigate a model that integrates the perspectives of self-organization and evolution. Our point of departure is the response threshold model, where we allow thresholds to evolve. We ask whether the thresholds will evolve to a state where division of labor emerges in a form that fits the needs of the colony. We find that division of labor can indeed evolve through the evolutionary branching of thresholds, leading to workers that differ in their tendency to take on a given task. However, the conditions under which division of labor evolves depend on the strength of selection on the two fitness components considered: amount of work performed and on worker distribution over tasks. When selection is strongest on the amount of work performed, division of labor evolves if switching tasks is costly. When selection is strongest on worker distribution, division of labor is less likely to evolve. Furthermore, we show that a biased distribution (like 3:1) of workers over tasks is not easily achievable by a threshold mechanism, even under strong selection. Contrary to expectation, multiple matings of colony foundresses impede the evolution of specialization. Overall, our model sheds light on the importance of considering the interaction between specific mechanisms and ecological requirements to better understand the evolutionary scenarios that lead to division of labor in complex systems
Common or multiple futures for end of life care around the world? Ideas from the âwaiting room of historyâ
Around the world there is growing interest in the manner in which care is delivered to people at the end of life. However, there is little unanimity on what constitutes a âgood deathâ and the appropriate societal responses to the issue of delivering culturally relevant and sustainable forms of end of life care in different settings are not subjects of broad agreement. In this critical conceptual paper we focus on the emerging narratives of global palliative care and offer an assessment of their implications. We relate this to calls to improve end of life care across jurisdictions and settings, attempts to map and grade the development of palliative care provision, and to the emergence of a widely recognised global âquality of death indexâ. We consider an alternative approach to framing this debate, drawn from a subaltern and post-colonial studies perspective and suggest that adopting a truly global perspective will require acceptance of the plurality of past and present local problems and issues relating to end of life care, as well as the plural possibilities of how they might be overcome. In that context, we would not aim to universalise or privilege one particular global future for end of life care. Instead of homogenising end of life interventions, we seek to be open to multiple futures for the care of the dying
Effects of acute and chronic temperature changes on the functional responses of the dogfish Scyliorhinus canicula (Linnaeus, 1758) towards amphipod prey Echinogammarus marinus (Leach, 1815)
Predation is a strong driver of population dynamics and community structure and it is essential to reliably quantify and predict predation impacts on prey populations in a changing thermal landscape. Here, we used comparative functional response analyses to assess how predator-prey interactions between dogfish and invertebrate prey change under different warming scenarios. The Functional Response Type, attack rate, handling time and maximum feeding rate estimates were calculated for Scyliorhinus canicula preying upon Echinogammarus marinus under temperatures of 11.3 °C and 16.3 °C, which represent both the potential daily variation and predicted higher summer temperatures within Strangford Lough, N. Ireland. A two x two design of âPredator Acclimatedâ, âPrey Acclimatedâ, âBoth Acclimatedâ, and âBoth Unacclimatedâ was implemented to test functional responses to temperature rise. Attack rate was higher at 11.3 °C than at 16.3 °C, but handling time was lower and maximum feeding rates were higher at 16.3 °C. Non-acclimated predators had similar maximum feeding rate towards non-acclimated and acclimated prey, whereas acclimated predators had significantly higher maximum feeding rates towards acclimated prey as compared to non-acclimated prey. Results suggests that the predator attack rate is decreased by increasing temperature but when both predator and prey are acclimated the shorter handling times considerably increase predator impact. The functional response of the fish changed from Type II to Type III with an increase in temperature, except when only the prey were acclimated. This change from population destabilizing Type II to more stabilizing Type III could confer protection to prey at low densities but increase the maximum feeding rate by Scyliorhinus canicula in the future. However, predator movement between different thermal regimes may maintain a Type II response, albeit with a lower maximum feeding rate. This has implications for the way the increasing population Scyliorhinus canicula in the Irish Sea may exploit valuable fisheries stocks in the future
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