16 research outputs found
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Power and Responsibility: The Role of the Sciences in Reducing Social Inequality
We explore the role of scientists in reducing social inequality through policy advice in conversation with Professors Danny Dorling and Andrew Stirling. Providing unbiased advice requires careful consideration of
the implicit power imbalances in policymaking and the internalised inequality within the scientific discipline itself. Professors Stirling and Dorling explain the causes and effects of the science-policy dynamic, and propose strategies to improve science advising and to address the underlying issues within scientific research
Modelling language for biology with applications
Understanding the links between biological processes at multiple scales, from
molecular regulation to populations and evolution along with their interactions with
the environment, is a major challenge in understanding life. Apart from understanding
this is also becoming important in attempts to engineer traits, for example in crops,
starting from genetics or from genomes and at different environmental conditions
(genotype x environment → trait). As systems become more complex relying on
intuition alone is not enough and formal modelling becomes necessary for integrating
data across different processes and allowing us to test hypotheses. The more complex
the systems become, however, the harder the modelling process becomes and the
harder the models become to read and write. In particular intuitive formalisms like
Chemical Reaction Networks are not powerful enough to express ideas at higher levels,
for example dynamic environments, dynamic state spaces, and abstraction relations
between different parts of the model. Other formalisms are more powerful (for example
general purpose programming languages) but they lack the readability of more domain
specific approaches.
The first contribution of this thesis is a modelling language with stochastic semantics,
Chromar, that extends the visually intuitive formalisms of reactions, in which simple
objects, called agents, are extended with attributes. Dynamics are given as stochastic
rules that can operate on the level of agents (removing/adding) or at the level of attributes
(updating their values). Chromar further allows the seamless integration of time and
state functions with the normal set of expressions – crucial in multi-scale plant models
for describing the changing environment and abstractions between scales. This leads to
models that are both formal enough for simulations and easy to read and write.
The second contribution of this thesis is a whole-life-cycle multi-model of the
growth and reproduction of Arabidopsis Thaliana, FM-life, expressed in a declarative
way in Chromar. It combines phenology models from ecology to time developmental
processes and physical development, which allows to scale to the population and address
ecological questions at different genotype x environment scenarios. This is a step in
the path for mechanistic links between genotype x environment and higher-level crop
traits.
Finally, I show a way of using optimal control techniques to engineer traits of
plants by controlling their growth environmental conditions. In particular we explore
(i) a direct problem where the control is temperature – assuming homogeneous growth
conditions and (ii) indirect problem where the control is the position of the plants –
assuming inhomogeneous growth conditions
INFO2009 resource: Infographic on the evolution of Open Source Software
Infographic providing a timeline of important events in the history of open source software since the fifties. Also includes stats for OSS licenses, usage in Business and reasons for participating in an OSS community
A multiscale analysis of early flower development in Arabidopsis provides an integrated view of molecular regulation and growth control.
We have analyzed the link between the gene regulation and growth during the early stages of flower development in Arabidopsis. Starting from time-lapse images, we generated a 4D atlas of early flower development, including cell lineage, cellular growth rates, and the expression patterns of regulatory genes. This information was introduced in MorphoNet, a web-based platform. Using computational models, we found that the literature-based molecular network only explained a minority of the gene expression patterns. This was substantially improved by adding regulatory hypotheses for individual genes. Correlating growth with the combinatorial expression of multiple regulators led to a set of hypotheses for the action of individual genes in morphogenesis. This identified the central factor LEAFY as a potential regulator of heterogeneous growth, which was supported by quantifying growth patterns in a leafy mutant. By providing an integrated view, this atlas should represent a fundamental step toward mechanistic models of flower development