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CatLady78

Profile Information

Gender: Female
Current location: India
Member since: Thu Jun 18, 2020, 11:40 AM
Number of posts: 497

About Me

I am an old-timer. I posted here as nam78_two for 4-5 years (2004 or 5 to 2009-10) in the Bush, Obama years.

Journal Archives

This is horrible-we are a nightmarishly cruel species

This has to be stopped.

Sad

I suppose this will be the next 100 years...more articles about one species after another going extinct...

...

I actually post science here to an extent to force myself to read more stuff and in more depth.
I made an embarassing error in an article I just posted on something I have a passing familiarity with-hair cell stereocilia. But it is making me read that paper properly.
Or I increasingly never do any reading outside a very narrow area in science and tied to specific problem solving.

As long as I don't leave anything inaccurate up here, it is an exercise that helps me. I'd hate to give people wrong information. So it forces me to check my work.

I am glad you contacted them and made these points

Thank you for doing that. I disagree very little with your points or with those by RobinA. I hope you prevail.

That said, I do still support PP for the simple reason that they are the most high profile organization that does the work they do. If they diluted their actual positions on birth control, abortion, gave a wider berth to religion/superstition/ anti science etc that would cause me real concern.

I simply do not know another org of that stature. They face constant smearing (as does Sanger) by religious zealots who are fairly tolerant of actual racists but suddenly become concerned about racism or the poor, when it is PP, Sanger, Paul Ehrlich, David Attenborough, Michael Moore...just about any feminist, environmentalist, scientist or liberal they can smear.
It is as hollow as Tucker Carlson's populism.

It is a cynical ploy and has little to do with concerns over the rights of the poor, racism etc.

Love Bill Nye.nt

This is a great post

Thank you for expressing these ideas so well. If we have lost the ability to comprehend shades of grey as a species, that is net a win for rightist thinking.

The Gliding Motion of Toxoplasma gondii

This is neat. These scientists have further characterized the movement of Toxoplasma gondii, which uses a type of gliding movement that is faster than a lot of cell movement (which is analogous to crawling). The cell anchors itself at a couple of points on a surface which mimics the exterior of the cell. It contracts and builds up spring energy in its cytoskeleton, which it then uses to propel itself forward upon the breaking of those same attachments.
(Apologies for the clumsiness in my writing-my scientific communication skills are a work in progress. I am still a little confused by this paper. I will update this if I have said anything inaccurate.)

https://www.acs.org/content/acs/en/pressroom/presspacs/2020/acs-presspac-june-17-2020/how-toxoplasma-parasites-glide-so-swiftly-video.html


Image credit: The Tardieux lab (it is from the paper).

If you're a cat owner, you might have heard of Toxoplasma gondii, a protozoan that sometimes infects humans through contact with contaminated feces in litterboxes. Although harmless to most people, T. gondii can cause serious illness or death in immunocompromised individuals or fetuses of infected pregnant women. Now, researchers reporting in ACS Nano have studied how the microorganism glides so swiftly through mammalian tissues during an infection.

To find out, the researchers combined several types of high-resolution and high-speed 2-D and 3-D live imaging with force microscopy methods. They examined the parasites' movements through collagen fibers that mimicked the extracellular matrix—a dense network of proteins that surrounds cells in tissues. Tachyzoites squeezed through the collagen meshwork by first pausing and forming a kink in the front part of their bodies. Then, the cell bodies contracted, and the parasites surged forward with a spring-like motion. Delving deeper with the help of photomicropatterning and machine learning approaches, the researchers found that these movements were caused by the formation and breakage of specific attachments between the protozoans and collagen fibers, resulting in the buildup of contractile forces in the parasites' cytoskeletons. When the front tip of a parasite released its hold on the fibers, it sprung forward with a super-fast, helical glide.

Neat video:


I disagree with the attacks on Sanger

Anti-abortion groups have been attacking her for a long time:

https://www.snopes.com/fact-check/margaret-sanger-weeds/

I get why PP has to do this. However, I disagree with the attacks on Sanger. They lack perspective. If she was alive today I would imagine she would be staunchly opposed to racism. She was a progressive leader by the standards of her time. The attacks on her are mostly driven by actual racists. Where that is not the case, I just have a different view-point. Fifty years from now a lot of us will be condemned for our beliefs and ways today-especially the ignoring of environmental issues and our lack of concern for other species and for future generations.

I am with you - she was a product of her times

If she were alive today she would have progressed in her views (unlike those who attack her from the right). In her time, there was widespread support for eugenics-a huge error but the irony is that those who fake outrage over it from the right (think Fox News, the GOP etc) still think like that today. We have to learn to separate people who were imperfect or made errors from the irredeemably regressive.
Unlike many of those who attack her, she actually did a lot of good.

That said, PP is doing the right thing strategically for the simple reason that they face many attacks as is. Their work is very important-anything that lets the actual racists and sexists from the right smear them more easily is best dispensed with. Fortunately a lot of these smears also come from incredibly stupid people like James O'Keefe.

Personalized Microbots Can Deliver Drugs to Mammalian Cells

That is neat...hybrid microbots for drug delivery..

https://publishing.aip.org/publications/latest-content/personalized-microrobots-swim-through-biological-barriers-deliver-drugs-to-cells/


Personalized Microrobots Swim Through Biological Barriers, Deliver Drugs to Cells


Illustration (top) and scanning electron microscopy image (bottom) of biohybrid bacterial microswimmers, which were fabricated by combining genetically engineered E. coli MG1655 and nanoerythrosomes made from red blood cells. A biotin-streptavidin interaction was used to attach nanoerythrosomes to the bacterial membrane. CREDIT:Image courtesy of the authors

WASHINGTON, April 7, 2020 — Tiny biohybrid robots on the micrometer scale can swim through the body and deliver drugs to tumors or provide other cargo-carrying functions. The natural environmental sensing tendencies of bacteria mean they can navigate toward certain chemicals or be remotely controlled using magnetic or sound signals.

To be successful, these tiny biological robots must consist of materials that can pass clearance through the body’s immune response. They also have to be able to swim quickly through viscous environments and penetrate tissue cells to deliver cargo.

In a paper published this week in APL Bioengineering, from AIP Publishing, researchers fabricated biohybrid bacterial microswimmers by combining a genetically engineered E. coli MG1655 substrain and nanoerythrosomes, small structures made from red blood cells.

Nanoerythrosomes are nanovesicles derived from red blood cells by emptying the cells, keeping the membranes and filtering them down to nanoscale size. These tiny red blood cell carriers attach to the bacterial membrane using the powerful noncovalent biological bond between biotin and streptavidin. This process preserves two important red blood cell membrane proteins: TER119 needed to attach the nanoerythrosomes, and CD47 to prevent macrophage uptake.

The E. coli MG 1655 serves as a bioactuator performing the mechanical work of propelling through the body as a molecular engine using flagellar rotation. The swimming capabilities of the bacteria were assessed using a custom-built 2D object-tracking algorithm and 20 videos taken as raw data to document their performance.

Biohybrid microswimmers with bacteria carrying red blood cell nanoerythrosomes performed at speeds 40% faster than other E. coli-powered microparticles-based biohybrid microswimmers, and the work demonstrated a reduced immune response due to the nanoscale size of the nanoerythrosomes and adjustments to the density of coverage of nanoerythrosomes on the bacterial membrane.

These biohybrid swimmers could deliver drugs faster, due to their swimming speed, and encounter less immune response, due to their composition. The researchers plan to continue their work to further tune the immune clearance of the microrobots and investigate how they might penetrate cells and release their cargo in the tumor microenvironment.
“This work is an important stepping stone in our overarching goal of developing and deploying biohybrid microrobots for therapeutic cargo delivery,” author Metin Sitti said. “If you decrease the size of red blood cells to nanoscale and functionalize the body of the bacteria, you could obtain additional superior properties that will be crucial in the translation of the medical microrobotics to clinics.”


Edit: I edited the title in the interests of truth in advertising . This article has nothing whatsoever to do with the delivery of drugs to prison cells!


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