Wednesday, November 20, 2019

Transiting Ethiopia, Travelling to Zuid Afrika and Vaccines

It has been a long while since I blogged about anything, and it can be blamed perhaps on my teaching commitments, unfinished research papers and PhD students whose defence dates are up and the levels of stress are just a little more than anybody should have to deal with.

So it was with glee that I registered for a conference in Zuid Afrika (ZA) on bacterial virulence in November 2019 (BMSV, Cape Town) organized by a group of experts on Tuberculosis.
Yellow Fever Virus Particle: A rendering from RayUr.com

Little did I know what extra adminisrative burden I was bringing onto myself. However, adding to my task-overload was the fact that I needed to prepare for the journey in a manner I had not so far required - vaccination! Indeed with all the strange rumour mongering about vaccines, it was surprising to come accross some clearly detailed list of places which if one transits or travels through, to re-enter India I will compulsorily need to be vaccinated against the Yellow Fever (1).  To quote the site "Any person, Foreigner or Indian, (excluding infants below six months) arriving by air or sea without a vaccination certificate of yellow fever will be kept in quarantine isolation for a period up to 6 days if :
  • He arrives in India within 6 days of departure/transit from a yellow fever endemic area.
  • Has come on a ship which has started from or transited at any port in a yellow fever endemic country within 30 days of its arrival in India provided such ship has not been disinfected in accordance with the procedure laid down by WHO."
 The insistence on "He" is theirs not mine. I would have preferred (the now archiac) s/he or even "Person(s)" to be gender neutral and non-binary.

The world health organization (WHO) describes the illness as an "...an acute viral haemorrhagic disease transmitted by infected mosquitoes...." (2) and the yellow-tag name comes from the fact that affected patients show jaundice (yellow) pallor. Jaundice in turns is a symptom of excess bilirubin in the blood, an effect of an underlying condition. The origins of bilirubin are of course the famed hemoglobin. The breakdown is described by the following (schematic) reactions (3,4):

Hb ----> Globin + Fe + Haeme
Haeme -----> Biliverdin -----> Bilirubin

The location of this degradation process is in the liver, spleen and bone marrow.

Thus the kind of infections that trigger excess breakdown of RBCs and Hb are grouped under haemolytic jaundice (as opposed to hepatic jaundice caused by liver dysfuntion कवेळी ).

To once more quote WHO, "The yellow fever virus is an arbovirus of the flavivirus genus and is transmitted by mosquitoes, belonging to the Aedes and Haemogogus species." In short it means transmission by mosquitoes and viral with surprisingly (acc. to WHO) no cure available, with help to prevent dehydration and liver failure improving patient outcomes (5).

Interesting the virus is a +ve sense ssRNA virus, i.e. its genome acts like an mRNA when it enters a host cell! The capsid structure of this Flavivirus (Latin "flavi" = yellow) is similar to that of the dengue and west-nile virus. Indeed endocytosis and ER targetting appear to be the modus operandi at the level of the single cell.

 Much more remains to be done on this account, and perhaps as I expectantly wait for a jab, thoughts about potential engineering vaccines as opposed to the live, weakened virus that is currently administered (6).

So more to travelling scientists and spreading the good science, and better understanding the world around us.


References:
1) Bureau of Immigration, Govt. of India https://boi.gov.in/content/health-regulation
2) Yellow Fever, WHO https://www.who.int/news-room/fact-sheets/detail/yellow-fever
3) Hemoglobin catabolism and bilirubin http://chemistry.elmhurst.edu/vchembook/634bilirubin.html 
4) Bilirubin Metabolism http://www.meddean.luc.edu/lumen/MedEd/orfpath/bilirub.htm
5) Yellow Fever Treatment https://www.who.int/csr/disease/yellowfev/en/
6) Yellow fever vaccine https://www.cdc.gov/vaccines/hcp/vis/vis-statements/yf.html


Tuesday, November 01, 2016

बांस Bamboo Mast

Bamboo has many legends and sayings associated with it, especially in asian cultures. In hindi (हिंदी) in India we say "Na rehaga baans, na bajegi bansuri", that is there is no hope of hearing sweet reed melodies if the bamboo stops growing. Many chinese charachteristics of strenghth, flexibility and virtue have been attributed by philosophers and poets to bamboo 
(the taller the bamboo grows, the more it bends ~ i.e. truly great people are humble).
From the perspective of the premise of this blog of patterns in nature, Bamboo mast (मास्ट) flowering or the mass synchronized flowering of these plants at the same time, with a long gap (30-120 years) counts with the big mysteries of "snychronization", with an added evolutionary and ecological context. The current ideas suggest a this mass flowering and seeding results in overwhelming the seed eaters by synchronization, giving the plants a survival chance exceeding the normal. Add on to that, bamboos out of sync do not do as well. And in such a context, changes in flowering time can only be integer multiples of the existing period. These integer values can also be reduced to primes by integer factorization (the same thing that lies at the heart of RSA encryption). And add to it, there is the excitement of a plant-biological alarm clock, ticking away. 

Further reading:
1) Synchronization http://www.scholarpedia.org/article/Synchronization
2) Keeley, JE; Keeley, J.E.; W.J. Bond (1999). "Mast flowering and semelparity in bamboos: The bamboo fire cycle hypothesis". American Naturalist. 154 (3): 383–391 https://www.ncbi.nlm.nih.gov/pubmed/10506551
3) Janzen, DH. (1976). "Why Bamboos Wait so Long to Flower". Annual Review of Ecology and Systematics. 7: 347–391. http://www.annualreviews.org/doi/10.1146/annurev.es.07.110176.002023


Monday, March 12, 2012

Cell Like Patterns in the Soil

Some pictures of patterns in non-living matter
The soil near Rameshwaram, possibly near brackish water. The white is probably the deposited salt. The cracking in the soil due to drying. And amazingly regular 'cells' formed in this breakup pattern. Almost appear to have a charachteristic size. Anybody with pointers to theories for this is welcome to comment. Interestingly looking at the size of the cells, it appears to reduce as the front gets closer to water. Something like  a dry state dependent cell-size. Beautiful to look at, and intriguing to think about.
And a nice cellular image to go with that. Seen above an image from Nowark et al. (2009, J. Cell. Biol.) showing a hexagonal geometry in mouse lens fibre cells.
Brings to mind the aphorism "just because things look the same, doesn't mean their underlying causes are the same". And yet.

Wednesday, October 12, 2011

Neuro Concious Tubulin

Microtubules, quantum coherence and conciousness were put together to the best of my knowledge by Sir Roger Penrose in his famous popular book "The Emperor's New Mind". However a not so recent report I came across about a study in the journal Science appears to to put cold water on it.

Charles Seife (2000) Cold Numbers Unmake the Quantum Mind Science Vol. 287 (5454), p791, DOI: 10.1126/science.287.5454.791




Wednesday, May 04, 2011

Diffusion in cells

Diffusion in cells- been teaching the course bio435 - biophysics II or Physical Biology of the Cell or what i really do for a living or...
The fascinating part about diffusion is that it binds both historically and scientifically energy, matter and living-systems. Brown who discovered the motion named after him, was looking at pollen grains. And in order to convince himself it was not 'vital' force, he even went to the extent of grinding pieces of the pyramids of egypt, to see if they.moved (guaranteed to be dead). Einstein who described the relation between macroscopic viscosity and molecular movement is "the physicist". In his Wunderjahr (miracle year) of 1906 papers one of them, less popularly known as compared to the mass energy relations, was the relation between heat (Wärme) and molecular movement (Bewegung).

In the lab, we have been using fluorescence recovery after photobleaching (FRAP), an experimental technique, combined wirh some simple imageJ data extraction and loads of attempts at analyzing the data, to estimate molecular diffusion coefficients inside cells. Currently we find a few odd things.
A FRAP profile of an E. coli cell expressing GFP

1_ GFP diffuses faster in E. coli than we can bleach it out.
2_ Reducing the number of bleach pulses doesn't allow any measurable bleaching, i.e. our scanning system is too slow
3_ The recovery kinetics show heavy amounts of imaging-dependent bleaching. 

Did we not turn down the laser after the bleach?

More on this when i get to it.