Profile cover photo
Profile photo
Corina Marinescu
46,616 followers -
I am a collection of water, calcium and organic molecules, but not a single one of the cells that compose me knows who I am, or cares ...so why should you?
I am a collection of water, calcium and organic molecules, but not a single one of the cells that compose me knows who I am, or cares ...so why should you?

46,616 followers
About
Corina's posts

Post has attachment
Simple Harmonic Oscillation
In order for mechanical oscillation to occur, a system must posses two quantities: elasticity and inertia. When the system is displaced from its equilibrium position, the elasticity provides a restoring force such that the system tries to return to equilibrium. The inertia property causes the system to overshoot equilibrium. This constant play between the elastic and inertia properties is what allows oscillatory motion to occur.

The animated gif shows the simple harmonic motion of three undamped mass-spring systems, with natural frequencies (from left to right) of ωo, 2ωo, and 3ωo. All three systems are initially at rest, but displaced a distance xm from equilibrium.

Source:
http://www.acs.psu.edu/drussell/Demos/SHO/mass.html

Reference:
http://farside.ph.utexas.edu/teaching/315/Waves/node4.html
http://scipp.ucsc.edu/~haber/ph5B/sho09.pdf

#physics #sho #science 
Animated Photo

Post has attachment
"What does it feel like to be lonely? It feels like being hungry: like being hungry when everyone around you is readying for a feast."

The Lonely City - an interesting book I find intriguing, at least for now.

#bookshelf #TheLonelyCity 
Photo

Post has attachment
Folding rings

work by Charlie Deck

#math #animation #processing

Animated Photo

Post has attachment
The Testes Are Connected to the Immune System?
Some parts of the body – including the tissues of the brain and testes – have long been considered to be completely hidden from our immune system.

Last year scientists made the amazing discovery that a set of previously unseen channels connected the brain to our immune system; now, it appears we might also need to rethink the immune system's relationship with the testes, potentially explaining why some men are infertile and how some cancer vaccines fail to provide immunity.

Researchers from University of Virginia School of Medicine discovered a 'very small door' which allows the testes to expose some of its antigens to the immune system without letting it inside.

For the past four decades the testes have been regarded as having 'immune privilege', meaning they don't mount an immune response when introduced to materials the immune system considers foreign.

Together with the brain, eyes, and placenta, inflammation in these parts of the body would be seriously bad news, which could explain why they are all physically or chemically hidden from the white cells and antibodies which protect us from infection.

This 'immunity from immunity' means any sperm outside of the testes can produce an autoimmune reaction, proving that the body considers its own sperm as foreign.

At least that's the current thinking, which might need to be modified if this new research is verified.

Separating the sperm-producing tissues in the testes from the blood vessels is a layer of tissue called Sertoli cells, serving as a kind of nurse cell to the developing sperm.

Sertoli cells lock together in such a way that they effectively form what's called a 'blood-testes barrier', preventing T-cells in the blood from sniffing out the growing sperm.

The system works well, but isn't foolproof – in up to 12 percent of men with spontaneous infertility, the immune system recognizes a chemical on the surface of sperm cells called the meiotic germ cell antigen (MGCA), suggesting they've met previously and don't tolerate it as native to the body.

The immunologists hypothesized this particular autoimmune response might say more about a break-down in tolerance than a break in the blood-testes barrier, suggesting that there were reasons to suspect MGCA wasn't as hidden as previously thought.

By focusing on two types of MGCA in normal and genetically altered mice and analyzing the mouse's T-cell tolerance to the antigens, the researchers found the Sertoli cells can 'leak' some types of the antigen into the blood vessels.

"In essence, we believe the testes antigens can be divided into those which are sequestered [behind the barrier] and those that are not," said researcher Kenneth Tung.

Not only could this discovery provide insight into how infertility can arise in some men, it could also help immunologists understand how cancer cells sequester, or hide, their own antigens, explaining why certain cancer vaccines can fail.

Paper:
https://www.jci.org/articles/view/89927

Read the story:
http://www.sciencealert.com/it-turns-out-the-immune-system-is-connected-to-the-testes-after-all

#research #immunesystem #testes #medicine 
Photo

Post has attachment
Scientists Create a New Kind of Liquid That Can Push Itself Along a Flat Surface
Moving a liquid from point A to point B typically requires either a sloping surface or a pump of some sort to apply pressure.

A new kind of material that is in early development requires neither, instead relying on a squirming skeleton of microscopic fibres to move it in a direction, opening the way for a class of fluid capable of worming itself through a channel.

Researchers from Brandeis University in Massachusetts took a hint from nature and investigated how the biomechanical properties of materials called microtubules could be applied to a mixture to make it move in a single direction around a container.

Read the story:
http://www.sciencealert.com/this-new-kind-of-liquid-can-push-itself-along-a-flat-surface-all-by-itself

Paper:
http://science.sciencemag.org/content/355/6331/eaal1979#Article%20in%20Science

Gif: A slow-motion animation of microtubules — the red lines — floating in a watery solution.

Video source:
https://www.youtube.com/watch?list=PLOtlWTwtHRXd922_RSmrUFknzZ0WnnTkp&v=RYPfQOvMmL8

#physics #fluiddynamics #science #research #microtubules 
Animated Photo

Post has attachment
Ganymede's Shadow
Approaching opposition early next month, Jupiter is offering some of its best telescopic views from planet Earth. On March 17, this impressively sharp image of the solar system's ruling gas giant was taken from a remote observatory in Chile. Bounded by planet girdling winds, familiar dark belts and light zones span the giant planet spotted with rotating oval storms. The solar system's largest moon Ganymede is above and left in the frame, its shadow seen in transit across the northern Jovian cloud tops. Ganymede itself is seen in remarkable detail along with bright surface features on fellow Galilean moon Io, right of Jupiter's looming disk.

Image & info via APOD
https://apod.nasa.gov/apod/astropix.html
Image Credit & Copyright: Damian Peach, Chilescope

#universe #nasa #ganymede #space #jupiter #science 
Photo

Post has attachment
SH2-155: The Cave Nebula
This skyscape features dusty Sharpless catalog emission region Sh2-155, the Cave Nebula. In the telescopic image, data taken through a narrowband filter tracks the reddish glow of ionized hydrogen atoms. About 2,400 light-years away, the scene lies along the plane of our Milky Way Galaxy toward the royal northern constellation of Cepheus. Astronomical explorations of the region reveal that it has formed at the boundary of the massive Cepheus B molecular cloud and the hot, young stars of the Cepheus OB 3 association.

The bright rim of ionized hydrogen gas is energized by radiation from the hot stars, dominated by the brightest star above and left of picture center. Radiation driven ionization fronts are likely triggering collapsing cores and new star formation within. Appropriately sized for a stellar nursery, the cosmic cave is over 10 light-years across.

Image & info via APOD
https://apod.nasa.gov/apod/astropix.html
Image Credit & Copyright: Eric Coles and Mel Helm

#space #nasa #universe #cavenebula 
Photo

Post has attachment
March 23 is reserved to Pierre-Simon Laplace
Today is the birthday of Pierre-Simon Laplace, a renowned mathematician, astronomer, and physicist. He was born in 1749 in Beaumount-en-Auge, France. Between 1770 and his election to the French Academy of Sciences in 1773, he submitted 13 papers to the academy, on such subjects as integral calculus, mechanics, and physical astronomy. His in-depth study of the motions of the planets and the stability of the solar system formed the basis of his seminal work, the five-volume Traité de Mécanique Céleste (Celestial mechanics; 1799–1825).

Because of the social and political upheaval brought on by the French Revolution, which began in 1789, Laplace left Paris with his wife and children. Unlike many of his colleagues, such as Antoine-Laurent de Lavoisier, Laplace managed to avoid being guillotined during the Reign of Terror. In 1795 the academy was reopened, and Laplace helped found the Bureau des Longitudes. Meanwhile, he continued his research and made important contributions to probability and statistics with the 1812 publication of Théorie Analytique des Probabilités. Laplace continued to produce papers well into his 70s before dying at age 77 in 1827.

Source:
http://physicstoday.scitation.org/do/10.1063/PT.5.031440/full/

#history #math #physics

Photo

Post has attachment
Spotless sun
The sun has had no sunspots, for 11 days, a spotless stretch that we have not seen since the last solar minimum.

Source:
https://sdo.gsfc.nasa.gov/gallery/potw/item/790?linkId=35710996

#nasa #SDO #sun #science 
Animated Photo

Post has attachment
Central Cygnus Skyscape
In cosmic brush strokes of glowing hydrogen gas, this beautiful skyscape unfolds across the plane of our Milky Way Galaxy near the northern end of the Great Rift and the center of the constellation Cygnus the Swan. A 36 panel mosaic of telescopic image data, the scene spans about six degrees. Bright supergiant star Gamma Cygni (Sadr) to the upper left of the image center lies in the foreground of the complex gas and dust clouds and crowded star fields.

Left of Gamma Cygni, shaped like two luminous wings divided by a long dark dust lane is IC 1318 whose popular name is understandably the Butterfly Nebula. The more compact, bright nebula at the lower right is NGC 6888, the Crescent Nebula. Some distance estimates for Gamma Cygni place it at around 1,800 light-years while estimates for IC 1318 and NGC 6888 range from 2,000 to 5,000 light-years.

Image & info via APOD
https://apod.nasa.gov/apod/astropix.html
Image Credit & Copyright: Robert Gendler, DSS, BYU

#universe #space #skyscape #milkyway #nebula #nasa

Photo
Wait while more posts are being loaded