Tag Archives: ScienceEveryDay

I shared this all the way back in 2012, and someone else just reshared it and the…

I shared this all the way back in 2012, and someone else just reshared it and the notification reminded me of it.  

It's pretty frickin' cool!

Reshared post from +Scott Anderson

Animated gif of IC1396, a nebula in the constellation of Cepheus. It contains the well-known Elephant's Trunk Nebula and is about 2400 ly distant. Illumined by a huge O star (HD 206267), it's one of the largest emission nebulae in the Northern hemisphere.

An emission nebula consists of a cloud of ionized gas. Lower intensity will result in a predominance of red light, as hydrogen has a low energy of ionization. Green and blue will start to emerge as the intensity of the emission rises. The dark portions in the foreground are interstellar dust blocking the light from behind.

From the artist's site, linked below:

Since astronomical objects are too far away, no real parallax can be imaged. Doe to that, I have developed a method to turn my images to various 3D-formats. My work flow is based on scientific data from the object, distance and the source of ionization are usually known. The different types of the nebulae has typical structures, pillar like formations must point to the source of ionization, the radiation pressure forms kind of hollow area, inside of the nebula, around newly born stars, dark nebulae must be at front of the emission ones to show, etc… rest of the missing information is then replaced with an artistic vision.

#sciencesunday   #scienceeveryday   #astronomy  

http://astroanarchy.blogspot.fi/2012/10/an-experimental-3d-animation-from-my.html

h/t http://thisisnthappiness.com

How do gut pathologies arise and why is our immune system unable to prevent it? I…

Reshared post from +Akinola Emmanuel

How do gut pathologies arise and why is our immune system unable to prevent it? I am happy to say that our lab at The University of Chicago believes that the answer is the abnormal activation of an ancient pathway and its effector protein Beta-Catenin.

The Wnt/Beta-Catenin pathway is highly evolutionarily conserved and has roles in everything from embryonic development to cel-cell communication. There's a good chance that if you look at any human cancers, the Wnt/Beta-Catenin pathway is negatively affected.

Our research, spearheaded by lead author Dr. Shilpa Keerthivasan, has shown that in patients with colitis or colon cancer, Beta-Catenin is highly expressed compared to healthy patients.

Incredibly, she worked out on the cellular level that this activation corrupts the function of T-cells that regulate the immune system (Tregs). Instead of suppressing the activation of the immune system, these Tregs instead cause inflammation. What makes matters worse is that the other T cells that become activated can no longer be shut down. In the gut, activation of T cells is fairly common because T cells are constantly coming in contact with bacteria (as can be seen in the image below). The gut has the highest concentration of immune cells so you can imagine that improper activation of these cells can have catastrophic effects. This is why it's really crucial to have normally functioning Tregs. Once these Tregs become corrupted, activation of the immune system spirals out of control. In fact, if you transfer these corrupted Tregs to healthy mice, they also develop gut inflammation.

These findings are huge because now we have a good idea as to how colitis and colon cancer can seemingly develop sporadically. The next step is finding out what activates this pathway in people. Don't worry, we're on it!

The press release (less jargon) can be found here: http://www.eurekalert.org/pub_releases/2014-02/uocm-bat022414.php
The article can be found here (unfortunately, it's behind a paywall) http://stm.sciencemag.org/content/6/225/225ra28.short?rss=1
Photo credits: http://scicasts.com/disease-processes/6438-location-in-the-body-where-immune-cells-reach-maturity-is-important-for-their-later-function/

#scienceeveryday  

How do gut pathologies arise and why is our immune system unable to prevent it? I am happy to say that our lab at The University of Chicago believes that the answer is the abnormal activation of an ancient pathway and its effector protein Beta-Catenin.

The Wnt/Beta-Catenin pathway is highly evolutionarily conserved and has roles in everything from embryonic development to cel-cell communication. There’s a good chance that if you look at any human cancers, the Wnt/Beta-Catenin pathway is negatively affected.

Our research, spearheaded by lead author Dr. Shilpa Keerthivasan, has shown that in patients with colitis or colon cancer, Beta-Catenin is highly expressed compared to healthy patients.

Incredibly, she worked out on the cellular level that this activation corrupts the function of T-cells that regulate the immune system (Tregs). Instead of suppressing the activation of the immune system, these Tregs instead cause inflammation. What makes matters worse is that the other T cells that become activated can no longer be shut down. In the gut, activation of T cells is fairly common because T cells are constantly coming in contact with bacteria (as can be seen in the image below). The gut has the highest concentration of immune cells so you can imagine that improper activation of these cells can have catastrophic effects. This is why it’s really crucial to have normally functioning Tregs. Once these Tregs become corrupted, activation of the immune system spirals out of control. In fact, if you transfer these corrupted Tregs to healthy mice, they also develop gut inflammation.

These findings are huge because now we have a good idea as to how colitis and colon cancer can seemingly develop sporadically. The next step is finding out what activates this pathway in people. Don’t worry, we’re on it!

The press release (less jargon) can be found here: http://www.eurekalert.org/pub_releases/2014-02/uocm-bat022414.php
The article can be found here (unfortunately, it’s behind a paywall) http://stm.sciencemag.org/content/6/225/225ra28.short?rss=1
Photo credits: http://scicasts.com/disease-processes/6438-location-in-the-body-where-immune-cells-reach-maturity-is-important-for-their-later-function/

#scienceeveryday  

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How to Build an Eye

Reshared post from +Buddhini Samarasinghe

How to Build an Eye

I came across a paper today with this fantastic image that I simply had to write about. Its another #OpenAccess paper, published in PLOS Biology (http://goo.gl/NmvA9). The image shows an eye from a human, mouse, zebrafish and a fruitfly. It also shows what happens when an important gene in eye development, pax6 is mutated. It's fascinating that despite all these differences between us and such a diverse range of species, we still share the same basic developmental pathways.

✤ The compound eye of a fruit fly is very different to our squidgy gelatinous eyeball. But the embryonic development of our eyes and the fruit fly eye are virtually identical. 

✤ In humans, a gene known as pax6 (in fruit flies it is known as eyeless) is a key player in eye development. As an aside, many Drosophila genes have interesting names because they were historically named after the visible effect of mutating that gene – see here for an old post of mine on funny fruit fly names (http://goo.gl/blIKBm).

✤ pax6 is known as a master control switch, and encodes a transcription factor which goes on to activate many other genes further downstream in the signaling pathway. Because it is crucial for eye development across so many different species, the amino acid sequence for pax6 is highly conserved across these species. For example, the mouse and human pax6 genes have identical amino acid sequences. Even more interestingly, mouse pax6 can trigger eye development in fruit flies. Finally, even though zebrafish and humans diverged over 400 million years ago, 96% of the amino acid sequence between the two genes are identical. 

✤ Injecting pax6 RNA into an early developing frog embryo results in the development of an ectopic eye (see #OpenAccess paper here: http://goo.gl/qFtvR2). 

✤ Given how important pax6 is for eye development, it comes as no surprise that things go drastically wrong if there are mutations in the pax6 gene. In the image below, the top row of images show healthy eyes from a human, mouse, zebrafish and a fruit fly. The bottom row have eyes that failed to develop correctly because of a mutant pax6 or eyeless gene. The human mutations in pax6 may result in aniridia (absence of iris), corneal opacity , cataract (lens clouding), glaucoma, and long-term retinal degeneration. For mouse, the mutants show extremely small eyes with lens/corneal opacity and iris abnormality, and there is a large plug of persistent epithelial cells that remains attached between the cornea and the lens. For zebrafish, the mutants show a decreased eye size, reduced lens size, and malformation of the retina. Drosophila mutations cause loss of eye development. 

✤ The developmental pathway activated by the master switch pax6 is very complex. Research in several labs is directed towards characterizing this complex network of regulatory genes. By studying this essential 'master switch' gene, we can gather important information about congentital defects in babies involving eye development.

Image from http://goo.gl/NmvA9

#ScienceEveryday   #EvoDevo  

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Jupiter and the Sun are the two largest objects in our Solar System, and as they…

Reshared post from +Yonatan Zunger

Jupiter and the Sun are the two largest objects in our Solar System, and as they orbit around one another, they create regions where their gravity roughly cancels out. These are the Lagrangian points, created whenever two objects orbit one another: places where gravity is such that another small object can follow along in the orbit without being pulled in or out. And since things aren't getting pulled out of there, they get stuck in there as well: and so we have two large clumps of asteroids (and miscellaneous smaller space debris) in Jupiter's orbit. These are called the Trojan Asteroids; the group ahead of Jupiter is known as the Greek Camp, and the group behind it the Trojan Camp, with the asteroids in each camp being named after famous people in that war. Together, these two camps have as many asteroids as the Asteroid Belt.

Other stable patterns are possible, too: another one is what's called a 3:2 resonance pattern, asteroids whose motion gets confined to a basically triangular shape by the combined pull of Jupiter and the Sun. This group (for Jupiter) is called the Hilda Family, and their route forms a triangle with its three points at the two Lagrange points and at the point on Jupiter's orbit directly opposite it from the Sun. 

None of these orbits are perfectly stable, because each of these asteroids is subject to pulling from everything in the Solar System; as a result, an asteroid can shift from the Lagrange points to the Hilda family, and from the Hilda family to the Asteroid Belt (not shown), especially if it runs into something and changes its course. 

The reason that Pluto was demoted from planet to dwarf planet is that we realized that these things are not only numerous, but some of them are quite big. Some things we formerly called asteroids are actually bigger than Pluto, so the naming started to seem a little silly. So our Solar System has, in decreasing order of size, four gas giant planets (Jupiter, Saturn, Neptune and Uranus); four rocky planets (Earth, Venus, Mars, and Mercury); five officially recognized dwarf planets (Eris, Pluto, Haumea, Makemake, and Ceres); and a tremendous number of asteroids. (We suspect that there are actually about 100 dwarf planets, but the job of classifying what's an asteroid and what's actually a planet is still in progress — see the "dwarf planet" link below if you want to know the details)

Ceres orbits in the Asteroid Belt, about halfway between Mars and Jupiter, just inside the triangle of the Hilda Family; Pluto and Haumea are both in the distant Kuiper Belt, outside the orbit of Neptune but shepherded by its orbit in much the same way that the Hildas are shepherded by Jupiter; Makemake is what's called a "cubewano," living in the Kuiper Belt but unshepherded, orbiting independently; and Eris is part of the Scattered Disc, the even more distant objects whose orbits don't sit nicely in the plane of the Solar System at all, having been kicked out of that plane by (we believe) scattering off large bodies like Jupiter.

But mostly, I wanted to share this to show you how things orbit. This picture comes from the amazing archive at http://sajri.astronomy.cz/asteroidgroups/groups.htm, which has many other such pictures, and comes to me via +Max Rubenacker. 

More information about all of these things:
http://en.wikipedia.org/wiki/Lagrangian_point
http://en.wikipedia.org/wiki/Trojan_(astronomy)
http://en.wikipedia.org/wiki/Hilda_family
http://en.wikipedia.org/wiki/Dwarf_planet
http://en.wikipedia.org/wiki/Kuiper_belt
http://en.wikipedia.org/wiki/Scattered_disc

#ScienceEveryDay

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