Career Profile

When working with data to answer questions about a topic, I draw from my experience as a scientist. I like to work at the intersection of mathematics and other fields. I rely on open source tools in my daily work for their large supportive communities and their expandability.

Experiences

Self Employed

Jan 2019 - Present

Organisation and teaching of workshops on basic Data Science skills with spreadsheets, OpenRefine, R and Python. Data cleaning and analysis, development of R shiny dashboards. Organisation and moderation of online events including seminars and community meetups.

  • tools taught: R, RStudio, Python, Jupyter Notebooks
  • tools used: Vidyo, Zoom, Trello, GitHub, R, RStudio

Research Associate

Jan 2014 - Dec 2018
University of KwaZulu-Natal, School of Engineering, Durban, South Africa

Analysis of environmental data from several field campaigns, numerical modelling of hydro-ecosystems, field work and lab experiments for projects in estuarine hydro-ecology, oceanography, and algae biofuel research. Administrative tasks and acquisition of third party funds.

  • data analysis and management (using Unix Shell, Matlab, R, SQL)
  • mathematical modelling (differential equations, hydrodynamic models)
  • software installations for research group (linux server)
  • student training and supervision (Honours and Masters level)
  • field work (boat based sampling in estuaries and sea, analysis of water samples)
  • lab experiments (photo-bioreactor, wave tank experiments)
  • scientific writing
  • funding acquisition
  • project planning
  • training workshop organisation
  • field/lab instrument setup and servicing (multiparameter probes, PIV system, wave generator)

Postdoctoral Researcher

Jul 2010 - Dec 2013
University of KwaZulu-Natal, School of Life Sciences, Durban, South Africa

Mathematical modelling and field observations to understand microalgal dynamics in a large estuarine lake with highly variable environmental conditions.

  • mathematical modelling (differential equations)
  • statistical analyses (regression models, canonical correspondence analysis, multidimensional scaling)
  • field work (sampling in estuaries, microscopic analysis)
  • student supervision
  • scientific writing
  • project planning

Postdoctoral Researcher

Aug 2008 - Apr 2010
Max Planck Institute of Molecular Plant Physiology, Systems Biology, Potsdam, Germany

Development of mathematical models of the photosynthetic electron transport using coupled differential equations.

Researcher

Jan 2008 - Mar 2008
Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Ecosystem Modeling, Geesthacht, Germany

Development of a trait-based predator-prey model, which allows simulation of a continuum of different species and its adaptability to altered growth conditions using coupled differential equations.

Researcher

Sep 2004 - Dec 2007
University of Potsdam, Ecology/Ecosystem Modeling, Potsdam, Germany

My dissertation research focused on dynamics of aquatic organisms (phytoplankton, zooplankton) in dependence on environmental conditions. I used descriptive statistics, multiple regression models, and process-oriented dynamic simulation models to analyse 20-year field data and experimental data.

Research Internship

Apr 2004 - Jun 2004
University of Oslo, Department of Biology, Oslo, Norway

Simulating dynamics of aquatic micro-organisms and nutrients with a mathematical model (ordinary differential equations) and model analysis.

Projects

These projects show some of my work I did apart from my research which is documented in publications (see below).

Shiny App for the RCCPII Capacity Development Initiative - An R shiny app to visualise and help discovering insights from activities and beneficiaries of a Capacity Development Initiative in South Africa in 2018/19.
A model to simulate dynamics in a bioreactor - Model to simulate algae, nutrient and grazer dynamics in a chemostat process implemented in python.
Webpage for AS Guitars - Basic webpage for AS Guitars built with Jekyll, based on Agency theme.
Landing page for Ocean Turbulence Workshop at UKZN, Durban, 2018 - Landing page for a training workshop at UKZN built with Jekyll, based on Frisco template.

Teaching

Workshops with The Carpentries: I am teaching basic concepts in R (with tidyverse) and Python (with SciPy), but also general concepts of data organisation and reproducibility. All lessons are continously developed by the community and hosted on GitHub. In particular I contributed to the following lessons: Python Ecology, Python Social Sciences, R ecology.

Data Carpentry Workshops for Ecologists/Social Scientists

Universal Data Literacy - Data Organisation in Spreadsheets, Data Cleaning with OpenRefine, Data Analysis and Visualisation with R or Python, Data Management with SQL

taught in: April 2019, February 2019, January 2019, September 2018, July 2018, March 2018, January 2018, September 2017

Software Carpentry Workshops

Basic lab skills for research computing - The Unix Shell, Programming with R or Python, Version Control and Sharing with Git/GitHub

taught in: December 2018

Carpentries Instructor Training

Basics of educational psychology and instructional design and how to use these ideas in both intensive workshops and regular classes

taught in: March 2019

Blog-posts

My Blog - A blog to remember things I learn when working with data and beyond
Tips and Tricks for Teaching R - Bianca Peterson & Katrin Tirok share their tried-and-tested tips and tricks for teaching R
Highlights from the recent Instructor Training in South Africa - New instructors from the East Coast of South Africa join The Carpentries community

Publications

Selected scientific papers demonstrating data analysis and mathematical modeling projects in my research.

Sediment resuspension in a shallow lake with muddy substrates: St Lucia, South Africa.
Zikhali, V., K. Tirok & D. Stretch (2015)
Continental Shelf Research 108: 112-120.
Wind-driven circulation patterns in a shallow estuarine lake: St Lucia, South Africa.
Schoen, J., D. Stretch & K. Tirok (2014)
Estuarine, Coastal and Shelf Science 146: 49-59.
Wind-driven waves in a shallow estuarine lake with muddy substrates: St Lucia, South Africa
Zikhali, V., K. Tirok & D. Stretch (2014)
Journal of Coastal Research, Special Issue No. 70, 729-735.
Predator-prey dynamics driven by feedback between functionally diverse trophic levels.
Tirok, K., B. Bauer, K. W. Wirtz & U. Gaedke (2011)
PLoS one 6: e27357.
A minimal mathematical model of non-photochemical quenching of chlorophyll fluorescence.
Ebenhöh, O., T. Houwaart, H. Lokstein, S. Schlede & K. Tirok (2011)
Biosystems 103: 196-204.