Csmsdust

Feeling like a pro in Atomic Force Microscopy

...to be honest I probably should really tell myself that at this point I really am the professional in this method. After 4 years of working with 2 different atomic force microscopes, now I started with a 3rd one, again a new type from a different company.

Only after 2 hours of training on the new machine, I could observe membranes of resistant bacteria all by myself. The membranes are the yellow pancakes sitting flat on the dark support. They are less than 8 nm high (0.000000008 m), as is visible in the blue and red profile lines. So it's super tricky to actually see them. Atomic force microscope touches the surface of my membranes and surrounding support with a tiny tip like with a finger and reconstructs the surface topology. On top of the small size, the cellular membranes are super soft so also the touching finger must be super soft to see them without damaging them.

There are many postdocs in academia, but not so many permanent researchers.

A new paper shows a statistics on where hundreds of Biomedical Sciences PhD graduates eventually ended up 10 years or more after graduation.

Federation of American Societies for Experimental Biology

From goal to outcome: Analyzing the progression of biomedical sciences PhD careers in a longitudinal study using an expanded taxonomy

Using a taxonomy that delineates key milestones, this study analyzed biomedical PhD student career goals and outcomes. We related career goa

What strikes me there:

1. Sooo many postdocs go to administration positions after their postdoc is finished.

And it's true! I know so many people in administration who were good scientists before!

The following graph shows that from 418 PhD graduates, 325 went for a postdoc and 93 didn't. 145 administration/management/operation (AMO in the graph) positions in the end is for me a bit shocking.

2. The time for a postdoc in academia to actually get a permanent/non trainee position can be up to 13 years!

Only half of the people makes in in 6 years after OhD graduation. That's much longer than getting a permanent job in administration. I do not want to be 13 years postdoc. This is also one of the reasons people quit academia.

There are many more facts in the original article. Go read it if you're interested.

Quantum biology, doodles while listening to a lecture and a little book of ideas/ research✨️

“but would you know yourself if you weren’t burning”

— Shane McCrae, from “The Pillar Was a Man He Had Been Stretched So Long and Thin,” BOAAT (Vol. 2)

Mouse embryo (day 12.5) stained for motor (red) and sensory (magenta) nerves and nerve endings (cyan)

By Dr. Gist F. Croft, Lauren Pietila, Dr. Ali H. Brivanlou (The Rockefeller University - Laboratory of Stem Cell Biology and Molecular Embryology)

Technique: Light Sheet Microscopy and Tissue Clearing (iDISCO)

Magnification 1.8x (objective lens magnification)

Hello! Why did penguins evolve to have black feathers if they live in icy (mostly white?) locations? I understand them having a white tummy because when swimming they could be more difficult to identify by a predator swimming below them? Thanks!

Love your blog!

Hello! So, here's what I learned at uni:

the widely-accepted reason penguins have black feathers is the same reason they have white tummies, but backwards. When swimming, they are more difficult to identify by a predator swimming above them! You can see similar countershading in sharks and dolphins, and also on land animals like mountain goats and lizards. Overall, it helps to make animals less obvious when viewing from the side, because it reduces the obviousness of their shadow.

As to why penguins have black feathers in icy, mostly white, locations (on LAND), you need to consider why it would be good to be white in an icy, white location in the first place!

Mostly, it would provide camouflage, which would protect from land predators! However, penguins don't really have any significant land predators in Antarctica. There are no polar bears, or big snakes, or even foxes or coyotes in Antarctica, so the penguin won't benefit from being camouflaged on land. Basically, there's no "selective pressure" for them to be all white!

some penguin chicks, however, do have to worry about a few predators, so they have a little more camouflage than the adult penguins:

What's more, there are likely advantages to black feathers in a cold environment like Antarctica! For example, in the sun, dark feathers absorb more thermal energy, helping to warm the penguin and maintain their body heat.

There may also be some stuff with black feathers being more resistant to wear/ friction drag in the water, but that's entering the realm of ongoing research, which I won't get into here.

Let me know if there's anything that needs clarifying!

(some citations if anyone wants further reading:)

Bonser, R. H. (1995). Melanin and the abrasion resistance of feathers. The Condor, 97(2), 590-591.

Ksepka, D. T. (2016). The penguin's palette--more than black and white: this stereotypically tuxedo-clad bird shows that evolution certainly can accessorize. American Scientist, 104(1), 36-44.

Rowland, H. M. (2009). From Abbott Thayer to the present day: what have we learned about the function of countershading?. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1516), 519-527.

Zagrai, A., & Hassanalian, M. (2020, July). Penguin coloration affects skin friction drag. In 2020 Gulf Southwest Section Conference.

I'm 50 pages in a book about quantum biology and it's my new favorite

Earth fractals from above