New paper by Gokul and Athmanathan (UG students): Fission-fusion dynamics in heterogeneous populations

Very happy that a very cool paper led by two former UG students of the lab – Gokul Nair and Athmanathan – is now published!

Screenshot 2019-03-14 at 11.11.26 AM

 

Gokul Nair, Athmanathan Senthilnathan, Srikanth Iyer, and Vishwesha Guttal, 2019, Fission-fusion dynamics and group-size dependent composition in heterogeneous populations, Physical Review E99, 032412, arXiv:1711.06882 [nlin.AO], Data and codes,  Download PDF. 

 

This is the first analytical model of fission-fusion dynamics in heterogeneous systems. Previous studies had looked at only homogeneous populations. We make interesting predictions: smaller groups are likely to be homogeneous while larger groups will be heterogeneous.

I really enjoyed working with these students and also with Prof Srikanth Iyer, who is a professor of Mathematics at IISc. My collaboration with Srikanth started with this project when we jointly advised Athmanathan, a UG student majoring in Math at IISc, for his UG project (Sept 2014- May 2015). While Athma formulated the model and got preliminary results, Gokul Nair (a UG physics Major from IISc) carried this on during his free-time, resolved many tricky mathematical issues, did more simulations and finally wrote the paper.

Although the paper is quite mathematical (perhaps most mathematical of all my papers so far), many sections are written in a way that is accessible to nonspecialists (you can easily skip mathsy parts without losing the essence – that was the attempt of our writing). I hope you will read and enjoy it!


Krishnapriya Tamma to join Azim Premji University as an Assistant Professor (updated)

I am absolutely delighted that Dr Krishnapriya Tamma – a postdoc from our lab – will soon (on 11th March 2019, Monday) be joining Azim Premji University as an Assistant Profesor! Hearty congratulations from the entire lab. Here is a picture from the lab party (Priya is on the right side, at the last minus one position)!

photo_2019-03-09_00-12-56

Priya completed her PhD from NCBS, working with Prof Uma Ramakrishnan. Priya joined our lab in April 2016 as a postdoctoral research associate. She was initially funded by a lab project grant and she then won the SERB National-Postdoctoral Fellowship award (from April 2017 onwards). Over these nearly three years, Priya has made immense contributions to the lab.

Priya helped us start a new direction of research in our lab on using remotely sensed vegetation data to infer the resilience of ecosystems. Her work with Sabiha (where both were equal contributors) is in nearly final stages of review and we hope to get that out soon! Priya also mentored Prashastha Mishra, an undergraduate student from IISER Pune and this led to another (in prep) manuscript on understanding the role of human influence in our characterisation of ecosystem states from remotely-sensed data. This is an area that we will continue collaborating for over the next few years. (In fact, we have just received a DBT grant – a post to come on that soon.)

Priya’s presence in the lab added a lot of energy and enthusiasm to the entire lab. We are badly going to miss that now. As soon as she joined, she resurrected our defunct lab meetings and made them full of excitement and fun. Apart from the research described above, she was also pursuing many collaborations with independently. Visit her Google Scholar profile to read her papers.

Priya is also interested in science communication, underprivileged groups and hopes to increase her engagement with these in the coming years, especially with a focus on Northeastern India. Update: To mention a few of her very important initiatives –  Priya was in the core organising committee of SCCS-Bengaluru for a few years and organized a pre-school for the underprivileged students.she also led discussions in CES In-house symposium on extremely important topics like mentor-mentee relationships, authorship issues, and how power-imbalance between mentor and mentee leads to suboptimal outcomes to many mentees, how to navigate such experiences, etc.

Azim Premji University has been hiring top-notch scientists and teachers over the last few years and is one of the best universities in India for undergraduate education. Once again, Congratulations to Dr Krishnapriya for her new job where I am absolutely sure that she will do a splendid job!


New book-chapter by Jitesh Jhawar et al: A first principle derivation of models of collective behaviour that account for finite group size

I am really pleased that a new publication – a first book chapter from lab and first paper of 2019 – is now out! Its led by Jitesh Jhawar, a final year PhD student in our lab and in collaboration with Richard Morris – a former postdoc at NCBS.

Jitesh Jhawar, Richard Morris, and Vishwesha Guttal, 2019, Deriving mesoscopic models of collective behaviour for finite populations, In Handbook of Statistics Vol 40: Integrated Population Biology and Modeling  (edited by Arni Srini Rao and C R Rao), Part B, 551-594. DOI: https://doi.org/10.1016/bs.host.2018.10.002;  Pre-print from Arxiv;  Codes and data on github.  Download PDF

Collective behaviours of animal groups are often modelled via agent-based simulations. They are relatively difficult to tract analytically. The main highlight here is that we present two analytical methods that are used in the literature (statistical physics and physical chemistry); we compare which method offers ease of model construction.

A second point worth highlighting is that most analytical methods often assume that group/population sizes are infinitely large. The methods we present accounts for the fact that real animal groups are finite in size and individuals interact with each other in inherently probabilistic ways! The resulting scale of description is also referred to as mesoscopic — a term that appears in the title of the book chapter.

The mesoscopic descriptions yield very counter-intuitive results,; for example, noise can actually facilitate collective order!!! Read the chapter for more details.

The writing style we have adopted is pedagogical so that even undergraduate students from physics and mathematics can understand the methods presented here.

Finally, I also want to highlight that the first author of the paper – Jitesh Jhawar – did his bachelor and masters degrees in Biotechnology – but in this chapter, he uses mathematical techniques like Fokker-Planck equations, Langevin equations, Ito Calculus, etc! So even biology background students can learn hard-core mathematical/theoretical biology if you really love doing theory! 

 

 


Understanding Behaviour – 2019 at Kolkata and Jitesh Jhawar wins best talk/poster prize

A number of folks from our lab — Abhratanu Saha (UG student), Akanksha (PhD student), Jitesh Jhawar (PhD student), Priya Iyer (postdoc), Preethi Rajasekaran (Project assistant), Nitin Saxena (PhD student) — attended the Understanding Behaviour – 2019 conference, organised by IISER-Kolkata.

Congratulations to Jitesh Jhawar – who won the best speed-talk cum poster award for his presentation on inferring local rules of interactions among fish from collective behaviour studies.

 

 


Jaideep Joshi awarded a prestigious Marie Curie fellowship

I am delighted that Jaideep Joshi, the (one of the) first PhD student of the lab, has been awarded a prestigious Marie Curie fellowship.

Jaideep will be pursuing his postdoctoral research in Austira/UK, mentored by Prof Ulf Dieckmann (IIASA, Vienna, Austria) and Prof Iain Colin Prentice (Imperial College London). His research topic is “Assessing the global vulnerability of forests to drought using Plant Functional Trait Evolution (Plant-FATE)”.

Soon after submitting his thesis (on the topic of spatial evolutionary dynamics), Jaideep joined Divecha Centre for Climate Change at IISc for a postdoctoral position. He will continue there for a few months before joining the Marie Curie fellows program.

Best wishes from the lab for his future endeavours!!!

 


Conferences 2018

Our lab members have attended a fairly large number of conferences in the year 2018. Here is a short summary of them.

Starting with me, I restricted my travel to a bare minimum due to family and child-care responsibilities. I did go to one a three-day meeting on Marine biology in Jan 2018 in France, followed by a DBT organised event on Nobel prize series in Rashtrapati Bhavan in early Feb 2018. After that, I have declined all conference invitations – both Indian and international. I will probably continue to limit my travel for at least another year.

Priya Iyer, an DST postdoctoral fellow, presented her work on parential care at a CNRS Jacques Monod conference “Sex uncovered: the evolutionary biology of reproductive systems” at Roscoff, France in April 2018.

Jitesh Jhawar (PhD student) attended and presented his work on fish schooling behaviour at a Conference on Collective Behaviour at ICTP, Trieste, Italy in May 2018. Interestingly, at this meeting, he met Dr Danny Raj, an Inspire Faculty Fellow at Chemical engineering department of our own institute! The conversations between them at Trieste has now led to a collaboration and Danny is a coauthor on a manuscript that we plan to submit very soon!

Krishnapriya Tamma (SERB supported National Postdoctoral Fellow), Sumithra Sankaran (PhD student) and Sabiha Majumder (a former PhD student and currently a postdoc Zurich) organised an Oral session titled “Multistability and Spatio-Temporal Dynamics of Abrupt Transitions in Terrestrial Ecosystems: Theory, Application and Management” at the Ecological Society of America 2018. It featured many talks by a diversity of speakers!  In the same meeting, all three of them also gave talks based on their own research work on ecosystem resilience carried out in our lab.

Krishnapriya Tamma also attended the Association for Tropical Biology and Conservation (ATBC) conference in Malaysia.

Sumithra Sankaran (PhD student), on the same trip to ESA 2018, attended Gordon conferences on “Unifying Ecology Across Scales Based on Individuals, Currencies or Theory”

Akanksha Rathore, a PhD student using machine learning techniques for collective behaviour, attended a Winter School on Quantitative Systems Biology: Learning and Artificial Intelligence at ICTP, Italy.

That’s it! Happy 2019!!


Sumithra Sankaran defends her PhD thesis!!!

I am super delighted to share this — somewhat belated — news that Sumithra Sankaran has defended her PhD thesis on 7th December 2018. Sumithra’s thesis was on understanding how local interactions, spatial patterns and ecosystem stability are related. Needless to say, Sumithra gave a fabulous presentation and the examiners (including external examiner Prof Partha Sarathi Dutta from IIT Ropar, Department of Mathematics) were super impressed.

It is worth noting – especially for prospective students to our lab – that Sumithra was formally trained in zoology and wildlife biology. Because of her exceptional interest in theory, she did a thesis in theoretical ecology involving fairly involved mathematical calculations, e.g., mean-field models, stochastic differential equations and their analyses via Fokker-Planck equations, cellular automata models. Finally, testing her predictions of theory with empirical data – which required another suite of skills in analysing remotely-sensed data, statistics, and making sense of results in light of theory!

Do check some of her papers here, here, here and here. There are two more being prepared.

Congratulations to Sumithra – its been so much fun collaboratingworking with you – which I hope we will continue!

Sumithra Sankaran showing a slide with spatially explicit model of patch dynamics.


Research project position for a duration of 5-6 months in the departments of Chemical engineering and CES [Update: Position filled]

UPDATE: The position has been filled.

Applications are invited for a research project position for a duration of 5-6 months in the departments of Chemical engineering and Centre for ecology, IISc Bangalore, India (Deadline for application: 06 Nov 2018). 

Broad research area: Understanding the agent-level interactions that give rise to the observed collective behaviour.

Project details: Project will be computational in nature; Project will involve developing optimization based methods to identify underlying interactions between a group of agents (like a school of fish or traffic) from the data of their motion and collective dynamics

About the project supervisor:

Dr Danny Raj M, INSPIRE faculty, Dept. of Chemical Engineering, IISc [dannym@iisc.ac.in– contact]

Website (for more details): http://dannyrajm.wixsite.com/danny-raj-m

The work will be done in collaboration with Dr Vishwesha Guttal, Associate Professor, Centre for ecological sciences, IISc Bangalore.https://teelabiisc.wordpress.com

Eligibility: Bachelor’s or Master’s degree from Engineering, Physics, Mathematics, Biological sciences; Final year projects for students in a Bachelor’s or Master’s degree

Skills desirable: Comfortable with building algorithms and coding (preferably in MATLAB; other packages like Python, Mathematica are also welcome); Penchant for analysing and understanding non-linear dynamics of systems

Details of salary: Candidates joining as project assistant or associate would get a salary commensurate of their experience and qualification; Candidates applying here for their final year projects are not eligible for a salary

Deadline for application: 06 Nov 2018

Contact: Interested candidates should email their resume to dannym@iisc.ac.in with the subject RESEARCH PROJECT POSITION- REG, stating why they are interested in the project (in brief) and how long they can commit to it. [The resume should detail any projects or interesting ventures undertaken that would be relevant for the post being offered].

Other details: An interview or test, will be held with the interested candidate following which the decision to offer the position will be made. The position is extendable based on the performance of the individual.


New paper by Jaideep Joshi: Demographic noise and cost of greenbeard can facilitate greenbeard cooperation

We are delighted to announce a new paper from the lab!

Jaideep Joshi and Vishwesha Guttal, 2018, Demographic noise and cost of greenbeard can facilitate greenbeard cooperation, Evolution, DOI: https://doi.org/10.1111/evo.13615

This is the second paper of our former PhD student Jaideep Joshi. Fantastic work, involving some hard-core analytical and simulational work to address an interesting problem on the evolution of greenbeard cooperation.

Congratulations to Jaideep!

While you are here, you must also check the previous paper of Jaideep on how mobility promotes cooperation, published last year in Plos Computational Biology.

 


Advise: On requesting recommendation letters

Many students ask me to write recommendation letters for a variety of purposes, like internship abroad, summer school and most importantly – graduate schools. It’s an important part of our job as academics to encourage younger and aspiring students. Therefore, in general, I am happy to write supporting letters if I know you ‘sufficiently well’. Here are some general tips to follow when you request me (or more generally it may apply to others whom you approach) to send recommendation letters – this information will help me to write better-supporting letters.

  • First, do write a short note requesting if the person you think is suitable to write a letter is willing to do so. When you do so, state the purpose of your application, attach your cv and mention the deadline.
  • In general, write at least a few weeks ahead of the deadline and clearly state what is the deadline. If the deadline is very short – you can still write, but be aware that many mentors may decline even if they feel you are a fantastic candidate.

Once I have agreed to send you the letter:

  • If it’s a graduate school application season, send a list of university, department, their respective deadlines, the program (PhD vs Masters), etc all in a single email.
  • Do send an updated CV every time you ask for a letter – even if I had sent a letter last year for a similar purpose. I would like to know how your cv has improved since last time, so that any modifications to the letter can be done.
  • Provide as much information on what is the recommendation for? And any other relevant information about the application. For example, if you wrote a proposal or statement of interest that is not confidential – share it with me. Share any pdf/link to details of what the application is asking. Sometimes, some advertisements are aimed for specific candidates with certain background (for ex: this conf is aimed for physicists interested in biology, or vice versa). Do point out them to me. A generic letter won’t help the selection to committee decide whether you are suitable.
  • A short note on any specific points that you would like me to highlight about you. It could be about your project/work done with me, about your grades, a new publication/work of yours that I am unaware of, or anything that you think will help your application. If you are applying to unusual programs (e.g. Masters in conservation biology but your background is in mathematics), tell me reasons for the same. Such information is very important and useful for me to write a good supporting letter.
  • Do not hesitate to remind me whether I have submitted the letter. Check the status at least a week, and a few days before, the deadline.
Some places (in Europe I think) as for recommendation letters to be sent via student herself/himself. As a general rule it’s not a good idea to have the letters sent via your own application; I think it actually weakens it (certainly in the way we write, and how they read). Always ask if there is a way professor can send it directly to them.
Finally, let me know the outcome of your application because I am curious to know, and am also interested in making sure you succeed. Moreover, its a basic courtesy to inform the outcome (even if its negative) to someone has invested time in writing a letter of recommendation. A negative outcome may also help your referee to improve the letter the next time you ask him/her.