fourteen things tagged “biology”

Peace Lily are Hard to Maintain

I have a dying peace lily. I’m a bit attached to it and don’t know that I’ll be able to save it. Searching the internet for any hope led me to this post (cached) which made me feel slightly better about my inexperience.

The first mistake is relying upon the plant’s visual cue that needs water: the leaves droop. But, as the post notes, this can happen when they’re both over and under-watered!

[…] This would be a good indicator of when to water, except that by the time things reach the point of laying flat, damage has been done: the roots die back slightly each time this happens, and if it happens often enough, it will eventually fail to come back at all.

[…] it’s difficult to get the watering just right. […] If it’s too wet, there’s a tendency for plants to rot where they sit, except that they do it in such a way that you don’t necessarily realize what’s going on. One day you go to pull off a dead leaf, and a whole rootless plant comes out. This will generally not be salvageable. To make things trickier, the plant (like a lot of other plants) responds to being too wet by – you guessed it – drooping, which would make an inexperienced grower think that it needs more water.

I think I ruined mine by transferring it to a larger pot, thinking I was ‘suffocating’ it in a smaller one.

However, it’s been my experience that, nine times out of ten, a peace lily with black leaf edges is suffering from root suffocation, either because its soil has broken down and compacted, or because part of the soil never gets to dry out. Especially in a very large pot, and especially especially in a plant that’s been overpotted (put in a pot that’s too large for the plant), and especially especially especially in a plant that’s in a very large pot, too big for the plant, with no drainage hole, the top of the soil can dry out while everything after the top three inches is soaking wet.

Contrary to marketing material, they are not easy beginner plants:

In the time I’ve been at Garden Web (since Dec. 2006), I’ve seen more people post about issues with their peace lilies than any other plant, no contest: too many marketers think that the only important thing about a plant is how much light it needs. It’s true that Spathiphyllum doesn’t require a lot of light; that doesn’t make it the best plant for you, any more than knowing Jennifer Anniston’s name makes her your best friend.

So what does one do?

Common sense is important. If your plant is droopy and the soil feels wet, the plant is obviously not drooping because it’s too dry: don’t give it water. If the plant looks fine and the soil feels dry, the plant doesn’t need water just because the soil is dry: wait for the leaves to get a little limp first. Spathiphyllums are nothing if not good communicators.

And don’t worry about humidity. And use progressively larger pots. I think mine is too far gone at this point 😔

The Schmidt Pain Index

This is the Schmidt Sting Pain Index, an eponymous and subjective measurement of the pain caused by bees, wasps, and ants (and other things in the order hymenoptera.) It ranges from 0-4. In Level Zero, you don’t feel any pain whatsoever; the stinger doesn’t even penetrate your skin. The humble and familiar honeybee will deliver a Level 2.

Schmidt describes Level 4, the absolute worst, as follows:

Bullet Ant

“Pure, intense, brilliant pain… like walking over flaming charcoal with a three-inch nail embedded in your heel”

“That really shuts you down. It really felt like a bullet. It was instantaneous, almost even before it stung me. It was absolutely riveting. There were huge waves and crescendos of burning pain—a tsunami of pain coming out of my finger. The tsunami would crash as they do on the beach, then recede a little bit, then crash again. It wasn’t just two or three of these waves. It continued for around 12 hours. Crash. Recede. Crash. It was absolutely excruciating. There wasn’t much I could do except be aware of it and groan.”

Tarantula Hawk

“Blinding, fierce [and] shockingly electric”

“A running hair dryer has just been dropped into your bubble bath”

“Like you were walking underneath a high-voltage electric line in a wind storm, a wind gust snapped the line, and it fell on your arm. You get 20,000 volts all at once cascading through your body. It’s pure electrifying pain. Instantaneous. Very clean and sharp.”

Warrior Wasp

“Torture. You are chained in the flow of an active volcano. Why did I start this list?”

Here’s Dr. Schmidt with a giant bug on his face.

Dr Justin O. Schmidt

Some quotes and that image are from this article he penned in Esquire (cached) where he touches upon why the pain profiles are different.

“Crowded, Compartmentalized, Sticky, Spatially Inhomogeneous”

In college, I remember being blown away by a huge, physical map of metabolic pathways our Biochemistry professor once brought into class. It looked like this:

metabolic pathways

Here it is online. Kinda like a Google Maps of cellular reactions. It was impressed upon us that the interior of a cell (especially a eukaryotic one) is a really, really busy and tight and ‘goopy’ place: “crowded, compartmentalized, sticky, spatially inhomogeneous”. As that paper notes, this messy, “macromolecular crowding” helps your proteins fold properly (among several other factors.) This was a bit hard for me to appreciate since, up to then, I was only accustomed to images of cells from a light microscope or vastly simplified illustrations school texts.

I was somehow reminded of all of that after seeing some astounding paintings by Professor David S. Goodsell (Wiki, Twitter, Website). He calls the series “Molecular Landscapes.” Here are a few related to the pandemic we’ve been through.

SARS-CoV-2 and Neutralizing Antibodies, 2020

Art by David S. Goodsell

Acknowledgement: David S. Goodsell, RCSB Protein Data Bank and Springer Nature; doi: 10.2210/rcsb_pdb/goodsell-gallery-025. The painting was commissioned for the cover of a special COVID-19 issue of Nature, presented 20 August 2020, and is currently in the collection of the Cultural Programs of the National Academy of Sciences.

(Unknown Title)

Art by David S. Goodsell

Acknowledgement: Illustration by David S. Goodsell

Coronavirus, 2020

Art by David S. Goodsell

Acknowledgement: Illustration by David S. Goodsell, RCSB Protein Data Bank; doi: 10.2210/rcsb_pdb/goodsell-gallery-019. This painting depicts a coronavirus just entering the lungs, surrounded by mucus secreted by respiratory cells, secreted antibodies, and several small immune systems proteins. The virus is enclosed by a membrane that includes the S (spike) protein, which will mediate attachment and entry into cells, M (membrane) protein, which is involved in organization of the nucleoprotein inside, and E (envelope) protein, which is a membrane channel involved in budding of the virus and may be incorporated into the virion during that process. The nucleoprotein inside includes many copies of the N (nucleocapsid) protein bound to the genomic RNA.

SARS-CoV-2 Fusion, 2020

Art by David S. Goodsell

Acknowledgement: Illustration by David S. Goodsell, RCSB Protein Data Bank; doi: 10.2210/rcsb_pdb/goodsell-gallery-026. This painting depicts the fusion of SARS-CoV-2 (magenta) with an endosomal membrane (green), releasing the viral RNA genome into the cell cytoplasm (blue), where it is beginning to be translated by cellular ribosomes to create viral polyproteins. The painting includes speculative elements that are designed to highlight the process, most notably, multiple states of the viral spike protein are shown.

SARS-CoV-2 mRNA Vaccine, 2020

Art by David S. Goodsell

Acknowledgement: Illustration by David S. Goodsell, RCSB Protein Data Bank; doi: 10.2210/rcsb_pdb/goodsell-gallery-027. Messenger RNA (mRNA) vaccines developed for the COVID-19 pandemic are composed of long strands of RNA (magenta) that encode the SARS-CoV-2 spike surface glycoprotein enclosed in lipids (blue) that deliver the RNA into cells. Several different types of lipids are used, including familar lipids, cholesterol, ionizable lipids that interact with RNA, and lipids connected to polyethylene glycol chains (green) that help shield the vaccine from the immune system, lengthening its lifetime following administration. In this idealized illustration, all of the lipids are arranged in a simple circular bilayer that surrounds the mRNA and the PEG strands have both extended and folded conformations. In reality, the structure may be less regular, as suggested in the NanoLetters paper […]

You Cannot Overcook Mushrooms

Note that you can certainly burn them. That’s not ‘cooking’, however. The key here is that mushroom cell walls are composed of chitin which is far more heat-stable by virtue of the structures it forms, compared to pectin which is what you’d find in veggies1.

In this video, Dan Souza explains all this and does something quite surprising when cooking mushrooms: He sautés the mushrooms in water to ‘collapse’ them prior to cooking them in just a teeny bit of oil (and the usual salt, pepper, butter, and herbs.) Amazing.

  1. You’ll also find chitin in the “exoskeletons of arthropods, such as crustaceans and insects, the radulae of molluscs, cephalopod beaks, and the scales of fish and skin of lissamphibians.” Leave it to fungi to be weird 😍🍄 ↩︎

On Consciousness

It is remarkable that mind enters into our awareness of nature on two separate levels. At the highest level, the level of human consciousness, our minds are somehow directly aware of the complicated flow of electrical and chemical patterns in our brains. At the lowest level, the level of single atoms and electrons, the mind of an observer is again involved in the description of events. Between lies the level of molecular biology, where mechanical models are adequate and mind appears to be irrelevant. But I, as a physicist, cannot help suspecting that there is a logical connection between the two ways in which mind appears in my universe. I cannot help thinking that our awareness of our own brains has something to do with the process which we call ‘observation’ in atomic physics. That is to say, I think our consciousness is not just a passive epiphenomenon carried along by the chemical events in our brains, but is an active agent forcing the molecular complexes to make choices between one quantum state and another. In other words, mind is already inherent in every electron, and the processes of human consciousness differ only in degree but not in kind from the processes of choice between quantum states which we call ‘chance’ when they are made by electrons.

Freeman Dyson

Paleoart

All Yesterdays is an exploration of things we know we will never know about “dinosaurs and prehistoric animals” . Jonathan Wojcik at bogleech.com has an excellent review of the book. Of particular interest: We know little-to-nothing about the creatures’ anatomies and morphologies because of missing soft tissue data. Here are paleoartists’ recreations of a cow and a swan:


Looked up a sperm whale’s skeleton and can’t imagine how lacking a recreation would be:

Source

This article discusses the history and current state of paleoart. And this post is the ultimate TL;DR on the subject

As C.M. Kosemen explains throughout All Yesterdays, we really can’t ever know how much fat and other soft tissues contributed to the overall shape of dinosaurs since that’s the first thing to rot and shrivel tight against their bones and like even a sperm whale has a little skinny skeleton.

so like


how would we know?