1,732 research outputs found
Recommended from our members
Establishing, Developing, and Sustaining a Community of Data Champions
Supporting good practice in Research Data Management (RDM) is challenging for higher education institutions, in part because of the diversity of research practices and data types across disciplines. While centralised research data support units now exist in many universities, these typically possess neither the discipline-specific expertise nor the resources to offer appropriate targeted training and support within every academic unit. One solution to this problem is to identify suitable individuals with discipline-specific expertise that are already embedded within each unit, and empower these individuals to advocate for good RDM and to deliver support locally. This article focuses on an ongoing example of this approach: the Data Champion Programme at the University of Cambridge, UK. We describe how the Data Champion programme was established; the programme’s reach, impact, strengths and weaknesses after two years of operation; and our anticipated challenges and planned strategies for maintaining the programme over the medium- and long-term
Recommended from our members
Intra-group relatedness affects parental and helper investment rules in offspring care
In any system where multiple individuals jointly contribute to rearing offspring, conflict is expected to arise
over the relative contributions of each carer. Existing theoretical work on the conflict over care has: (a)
rarely considered the influence of tactical investment during offspring production on later contributions to
offspring rearing; (b) concentrated mainly on biparental care, rather than cooperatively caring groups
comprising both parents and helpers; and (c) typically ignored relatedness between carers as a potential
influence on investment behavior. We use a game-theoretical approach to explore the effects of female
production tactics and differing group relatedness structures on the expected rearing investment contributed
by breeding females, breeding males, and helpers in cooperative groups. Our results suggest that the
breeding female should pay higher costs overall when helpful helpers are present, as she produces additional
offspring to take advantage of the available care. We find that helpers related to offspring through the
breeding female rather than the breeding male should contribute less to care, and decrease their contribution
as group size increases, because the female refrains from producing additional offspring to exploit them.
Finally, within-group variation in helper relatedness also affects individual helper investment rules by
inflating the differences between the contributions to care of dissimilar helpers. Our findings underline the
importance of considering maternal investment decisions during offspring production to understand
investment across the entire breeding attempt, and provide empirically testable predictions concerning the
interplay between maternal, paternal and helper investment and how these are modified by different
relatedness structures.This work was supported by a Natural Environment Research Council Studentship to the University of Cambridge
(J.L.S.) and by a Royal Society University Research Fellowship (A.F.R.)This is the author accepted manuscript. The final version can be found on the publisher's website at: http://link.springer.com/article/10.1007%2Fs00265-013-1595-5# © Springer-Verlag Berlin Heidelberg 201
Recommended from our members
Maternal costs in offspring production affect investment rules in joint rearing
When multiple individuals contribute to rearing the same offspring, conflict is expected to occur over the
relative amounts invested by each carer. Existing models of biparental care suggest that this conflict should
be resolved by partially compensating for changes by co-investors, but this has yet to be explicitly modeled
in cooperative breeders over a range of carer numbers. In addition, existing models of biparental and
cooperative care ignore potential variation in both the relative costs of offspring production to mothers and in
maternal allocation decisions. If mothers experience particularly high costs during offspring production, this
might be expected to affect their investment strategies during later offspring care. Here we show using a
game-theoretical model that a range of investment tactics can result depending on the number of carers and
the relative costs to the mother of the different stages within the breeding attempt. Additional carers result in
no change in investment by individuals when production costs are low, as mothers can take advantage of the
greater potential investment by increasing offspring number; however this tactic ultimately results in a
decrease in care delivered to each offspring. Conversely, when production costs prevent the mother from
increasing offspring number, our model predicts that other individuals should partially compensate for
additional carers and hence offspring should each receive a greater amount of care. Our results reinforce the
importance of considering investment across all stages in a breeding attempt, and provide some explanatory
power for the variation in investment rules observed across cooperative species.This work was supported by a Natural Environment Research Council studentship to
JLS, and by a Royal Society University Research Fellowship to AFR.This is the author accepted manuscript. The final version can be found on the publisher's website at: http://beheco.oxfordjournals.org/content/early/2012/11/20/beheco.ars203 © The Author 2012. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved
Recommended from our members
Maternal investment tactics in cooperative breeding systems
Whenever multiple individuals contribute to the care of offspring, the optimum level of investment for each carer depends on the behaviour of the others. Previous theoretical and empirical work has largely focused on carer contributions within a single stage of a breeding attempt, neglecting the potential for investment during earlier stages to influence later care decisions. Typically, mothers have much greater control than other carers over the number and quality of offspring, and hence by altering her investment during offspring production a mother can adaptively adjust offspring phenotype to match or exploit the predicted care paradigm. In this dissertation, I use theoretical, empirical and comparative methods to investigate the influence of maternal tactics on investment rules in cooperative breeding systems, where ‘helpers’ care in addition to parents. In three chapters I model maternal control of offspring quality and offspring number across a cooperative breeding attempt, and investigate how the costliness of different reproductive stages, the kin-structure of the care group, and the consequences of offspring early-life condition influence the investment rules of carers. During offspring rearing, fair division of labour within a cooperative group can theoretically be resolved using simple turn-taking rules, leading to efficient outcomes for all carers. To test whether such a rule is employed in nature, a later chapter analyses empirical provisioning data from the chestnut-crowned babbler (Pomatostomus ruficeps), a cooperatively breeding bird endemic to the Australian outback. I use a Markov chain Monte Carlo approach to determine whether individuals alter their provisioning rate when other carers visit the nest, and identify both ‘passive’ and ‘active’ turn-taking behaviour. Finally, I present a comparative analysis of studies on provisioning rules in cooperatively breeding birds, and investigate whether the level of investment mothers must contribute to offspring influences the later care paradigm observed. My results indicate that maternal costs contribute to variation in both breeding group size and female provisioning behaviour. I conclude that maternal investment tactics are an underappreciated influence on carer investment rules in
both the theoretical and empirical literature, and that incorporating them is crucial to understanding variation in cooperative care behaviour in nature.This PhD was funded by a studentship from the Natural Environment Research Council, and supplementary support from Peterhouse, Cambridge
Editorial: Cooperation and Coordination in the Family
Editorial on the Research Topic: Cooperation and Coordination in the Famil
Collapse of a Bose gas: kinetic approach
We have analytically explored temperature dependence of critical number of
particles for the collapse of a harmonically trapped attractively interacting
Bose gas below the condensation point by introducing a kinetic approach within
the Hartree-Fock approximation. The temperature dependence obtained by this
easy approach is consisted with that obtained from the scaling theory.Comment: Brief Report, 4 pages, 1 figure, Accepted in Pramana-Journal of
Physic
Clinical impact of anti-inflammatory microglia and macrophage phenotypes at glioblastoma margins
Glioblastoma is a devastating brain cancer for which effective treatments are required. Tumour-associated microglia and macrophages promote glioblastoma growth in an immune-suppressed microenvironment. Most recurrences occur at the invasive margin of the surrounding brain, yet the relationships between microglia/macrophage phenotypes, T cells and programmed death-ligand 1 (an immune checkpoint) across human glioblastoma regions are understudied. In this study, we performed a quantitative immunohistochemical analysis of 15 markers of microglia/macrophage phenotypes (including anti-inflammatory markers triggering receptor expressed on myeloid cells 2 and CD163, and the low-affinity-activating receptor CD32a), T cells, natural killer cells and programmed death-ligand 1, in 59 human IDH1-wild-type glioblastoma multi-regional samples (n = 177; 1 sample at tumour core, 2 samples at the margins: the infiltrating zone and leading edge). Assessment was made for the prognostic value of markers; the results were validated in an independent cohort. Microglia/macrophage motility and activation (Iba1, CD68), programmed death-ligand 1 and CD4+ T cells were reduced, and homeostatic microglia (P2RY12) were increased in the invasive margins compared with the tumour core. There were significant positive correlations between microglia/macrophage markers CD68 (phagocytic)/triggering receptor expressed on myeloid cells 2 (anti-inflammatory) and CD8+ T cells in the invasive margins but not in the tumour core (P < 0.01). Programmed death-ligand 1 expression was associated with microglia/macrophage markers (including anti-inflammatory) CD68, CD163, CD32a and triggering receptor expressed on myeloid cells 2, only in the leading edge of glioblastomas (P < 0.01). Similarly, there was a positive correlation between programmed death-ligand 1 expression and CD8+ T-cell infiltration in the leading edge (P < 0.001). There was no relationship between CD64 (a receptor for autoreactive T-cell responses) and CD8+/CD4+ T cells, or between the microglia/macrophage antigen presentation marker HLA-DR and microglial motility (Iba1) in the tumour margins. Natural killer cell infiltration (CD335+) correlated with CD8+ T cells and with CD68/CD163/triggering receptor expressed on myeloid cells 2 anti-inflammatory microglia/macrophages at the leading edge. In an independent large glioblastoma cohort with transcriptomic data, positive correlations between anti-inflammatory microglia/macrophage markers (triggering receptor expressed on myeloid cells 2, CD163 and CD32a) and CD4+/CD8+/programmed death-ligand 1 RNA expression were validated (P < 0.001). Finally, multivariate analysis showed that high triggering receptor expressed on myeloid cells 2, programmed death-ligand 1 and CD32a expression at the leading edge were significantly associated with poorer overall patient survival (hazard ratio = 2.05, 3.42 and 2.11, respectively), independent of clinical variables. In conclusion, anti-inflammatory microglia/macrophages, CD8+ T cells and programmed death-ligand 1 are correlated in the invasive margins of glioblastoma, consistent with immune-suppressive interactions. High triggering receptor expressed on myeloid cells 2, programmed death-ligand 1 and CD32a expression at the human glioblastoma leading edge are predictors of poorer overall survival. Given substantial interest in targeting microglia/macrophages, together with immune checkpoint inhibitors in cancer, these data have major clinical implications
Evolutionary Instability of Symbiotic Function in Bradyrhizobium japonicum
Bacterial mutualists are often acquired from the environment by eukaryotic hosts. However, both theory and empirical work suggest that this bacterial lifestyle is evolutionarily unstable. Bacterial evolution outside of the host is predicted to favor traits that promote an independent lifestyle in the environment at a cost to symbiotic function. Consistent with these predictions, environmentally-acquired bacterial mutualists often lose symbiotic function over evolutionary time. Here, we investigate the evolutionary erosion of symbiotic traits in Bradyrhizobium japonicum, a nodulating root symbiont of legumes. Building on a previous published phylogeny we infer loss events of nodulation capability in a natural population of Bradyrhizobium, potentially driven by mutation or deletion of symbiosis loci. Subsequently, we experimentally evolved representative strains from the symbiont population under host-free in vitro conditions to examine potential drivers of these loss events. Among Bradyrhizobium genotypes that evolved significant increases in fitness in vitro, two exhibited reduced symbiotic quality, but no experimentally evolved strain lost nodulation capability or evolved any fixed changes at six sequenced loci. Our results are consistent with trade-offs between symbiotic quality and fitness in a host free environment. However, the drivers of loss-of-nodulation events in natural Bradyrhizobium populations remain unknown
- …