10 research outputs found
Kinematic data
All kinematic data for predator-prey experiments
Supplementary Figures from A faster escape does not enhance survival in zebrafish larvae
An escape response is a rapid manoeuvre used by prey to evade predators. Performing this manoeuvre at greater speed, in a favourable direction, or from a longer distance have been hypothesized to enhance the survival of prey, but these ideas are difficult to test experimentally. We examined how prey survival depends on escape kinematics through a novel combination of experimentation and mathematical modelling. This approach focused on zebrafish (<i>Danio rerio</i>) larvae under predation by adults and juveniles of the same species. High-speed three-dimensional kinematics were used to track the body position of prey and predator and to determine the probability of behavioural actions by both fish. These measurements provided the basis for an agent-based probabilistic model that simulated the trajectories of the animals. Predictions of survivorship by this model were found by Monte Carlo simulations to agree with our observations and we examined how these predictions varied by changing individual model parameters. Contrary to expectation, we found that survival may not be improved by increasing the speed or altering the direction of the escape. Rather, zebrafish larvae operate with sufficiently high locomotor performance due to the relatively slow approach and limited range of suction feeding by fish predators. We did find that survival was enhanced when prey responded from a greater distance. This is an ability that depends on the capacity of the visual and lateral line systems to detect a looming threat. Therefore, performance in sensing, and not locomotion, is decisive for improving the survival of larval fish prey. These results offer a framework for understanding the evolution of predator–prey strategy that may inform prey survival in a broad diversity of animals
Matlab code
All code for the experimental analysis and mathematical simulations
preyStrategy_kinematicData
Kinematic data in Matlab-binary file
Mortality, expressed as Hazard Ratios with bias-corrected 95% confidence intervals for baseline data.
<p>Mortality, expressed as Hazard Ratios with bias-corrected 95% confidence intervals for baseline data.</p
COPD prognostic staging in high and low risk, according to the ES-FRC composite index.
<p>COPD prognostic staging in high and low risk, according to the ES-FRC composite index.</p
Kaplan Meier curves for the COPD population, categorized according to A) ES optimal threshold of 55%, B) ES subthresholds of 30 and 65%, C) FRC % predicted optimal threshold of 210% and D) ES-FRC composite index.
<p>Kaplan Meier curves for the COPD population, categorized according to A) ES optimal threshold of 55%, B) ES subthresholds of 30 and 65%, C) FRC % predicted optimal threshold of 210% and D) ES-FRC composite index.</p
Promoter Element Arising from the Fusion of Standard BioBrick Parts
We characterize the appearance of a constitutive promoter element
in the commonly used cI repressor-encoding BioBrick BBa_C0051. We
have termed this promoter element pKAT. Full pKAT activity is created
by the ordered assembly of sequences in BBa_C0051 downstream of the <i>cI</i> gene encoding the 11 amino acid LVA proteolytic degradation
tag, a BioBrick standard double-TAA stop codon, a genetic barcode,
and part of the RFC10 SpeI-XbaI BioBrick scar. Placing BBa_C0051 or
other pKAT containing parts upstream of other functional RNA coding
elements in a polycistronic context may therefore lead to the unintended
transcription of the downstream elements. The frequent reuse of pKAT
or pKAT-like containing basic parts in the Registry of Biological
Parts has resulted in approximately 5% of registry parts encoding
at least one instance of a predicted pKAT promoter located directly
upstream of a ribosome binding site and ATG start codon. This example
highlights that even seemingly simple modifications of a part’s
sequence (in this case addition of degradation tags and barcodes)
may be sufficient to unexpectedly change the contextual behavior of
a part and reaffirms the inherent challenge in carefully characterizing
the behavior of standardized biological parts across a broad range
of reasonable use scenarios
The evolution of non-small cell lung cancer metastases in TRACERx.
Metastatic disease is responsible for the majority of cancer-related deaths1. We report the longitudinal evolutionary analysis of 126 non-small cell lung cancer (NSCLC) tumours from 421 prospectively recruited patients in TRACERx who developed metastatic disease, compared with a control cohort of 144 non-metastatic tumours. In 25% of cases, metastases diverged early, before the last clonal sweep in the primary tumour, and early divergence was enriched for patients who were smokers at the time of initial diagnosis. Simulations suggested that early metastatic divergence more frequently occurred at smaller tumour diameters (less than 8 mm). Single-region primary tumour sampling resulted in 83% of late divergence cases being misclassified as early, highlighting the importance of extensive primary tumour sampling. Polyclonal dissemination, which was associated with extrathoracic disease recurrence, was found in 32% of cases. Primary lymph node disease contributed to metastatic relapse in less than 20% of cases, representing a hallmark of metastatic potential rather than a route to subsequent recurrences/disease progression. Metastasis-seeding subclones exhibited subclonal expansions within primary tumours, probably reflecting positive selection. Our findings highlight the importance of selection in metastatic clone evolution within untreated primary tumours, the distinction between monoclonal versus polyclonal seeding in dictating site of recurrence, the limitations of current radiological screening approaches for early diverging tumours and the need to develop strategies to target metastasis-seeding subclones before relapse