To Help Me Refer My Chemistry Resources To Students Who Seek Help, I Made A List of All The Chemistry

I'm pretty new here, and I don't actually know much about dinosaurs (just followed this blog because it seemed really cool and interesting) so could you explain what shrink-wrapped means?

Of course! See, modern animals have a lot of muscles, fat, fluff, etc, and end up looking very little like their actual skeleton. For example, look at how much fluff owls have:

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However, lots of palaeoartists completely ignore this! They basically stretch skin over the bones and call it a day. One especially bad example that was featured on @palaeofail is this poor pterosaur:

It barely has room for its digestive system. It’s definitely missing the air sac system that allows it to breathe. It’s got virtually no muscles on the arms - how does it fly?? - on the head (no wonder its mouth is open. It has no jaw muscles to close it!), on the torso (it needs to flap), or on the legs (walking) It doesn’t have any fat at all, so it’s definitely starving (maybe because it can’t fly or close its moth?). The skin is much too thin; you can see all of the bones and its wing membranes should be much, much thicker. And it’s missing the hair-like pycnofibres that should be covering its body!

Many palaeoartists have started to strike back at this by drawing modern animals like we might draw them if we found their bones:

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[House cat]

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New theory explains how beta waves arise in the brain

Beta rhythms, or waves of brain activity with an approximately 20 Hz frequency, accompany vital fundamental behaviors such as attention, sensation and motion and are associated with some disorders such as Parkinson’s disease. Scientists have debated how the spontaneous waves emerge, and they have not yet determined whether the waves are just a byproduct of activity, or play a causal role in brain functions. Now in a new paper led by Brown University neuroscientists, they have a specific new mechanistic explanation of beta waves to consider.

The new theory, presented in the Proceedings of the National Academy of Sciences, is the product of several lines of evidence: external brainwave readings from human subjects, sophisticated computational simulations and detailed electrical recordings from two mammalian model organisms.

“A first step to understanding beta’s causal role in behavior or pathology, and how to manipulate it for optimal function, is to understand where it comes from at the cellular and circuit level,” said corresponding author Stephanie Jones, research associate professor of neuroscience at Brown University. “Our study combined several techniques to address this question and proposed a novel mechanism for spontaneous neocortical beta. This discovery suggests several possible mechanisms through which beta may impact function.”

Making waves

The team started by using external magnetoencephalography (MEG) sensors to observe beta waves in the human somatosensory cortex, which processes sense of touch, and the inferior frontal cortex, which is associated with higher cognition.

They closely analyzed the beta waves, finding they lasted at most a mere 150 milliseconds and had a characteristic wave shape, featuring a large, steep valley in the middle of the wave.

The question from there was what neural activity in the cortex could produce such waves. The team attempted to recreate the waves using a computer model of a cortical circuitry, made up of a multilayered cortical column that contained multiple cell types across different layers. Importantly, the model was designed to include a cell type called pyramidal neurons, whose activity is thought to dominate the human MEG recordings.

They found that they could closely replicate the shape of the beta waves in the model by delivering two kinds of excitatory synaptic stimulation to distinct layers in the cortical columns of cells: one that was weak and broad in duration to the lower layers, contacting spiny dendrites on the pyramidal neurons close to the cell body; and another that was stronger and briefer, lasting 50 milliseconds (i.e., one beta period), to the upper layers, contacting dendrites farther away from the cell body. The strong distal drive created the valley in the waveform that determined the beta frequency.

Meanwhile they tried to model other hypotheses about how beta waves emerge, but found those unsuccessful.

With a model of what to look for, the team then tested it by looking for a real biological correlate of it in two animal models. The team analyzed measurements in the cortex of mice and rhesus macaques and found direct confirmation that this kind of stimulation and response occurred across the cortical layers in the animal models.

“The ultimate test of the model predictions is to record the electrical signals inside the brain,” Jones said. “These recordings supported our model predictions.”

Beta in the brain

Neither the computer models nor the measurements traced the source of the excitatory synaptic stimulations that drive the pyramidal neurons to produce the beta waves, but Jones and her co-authors posit that they likely come from the thalamus, deeper in the brain. Projections from the thalamus happen to be in exactly the right places needed to deliver signals to the right positions on the dendrites of pyramidal neurons in the cortex. The thalamus is also known to send out bursts of activity that last 50 milliseconds, as predicted by their theory.

With a new biophysical theory of how the waves emerge, the researchers hope the field can now investigate whether beta rhythms affect or merely reflect behavior and disease. Jones’s team in collaboration with Professor of Neuroscience Christopher Moore at Brown is now testing predictions from the theory that beta may decrease sensory or motor information processing functions in the brain. New hypotheses are that the inputs that create beta may also stimulate inhibitory neurons in the top layers of the cortex, or that they may may saturate the activity of the pyramidal neurons, thereby reducing their ability to process information; or that the thalamic bursts that give rise to beta occupy the thalamus to the point where it doesn’t pass information along to the cortex.

Figuring this out could lead to new therapies based on manipulating beta, Jones said.

“An active and growing field of neuroscience research is trying to manipulate brain rhythms for optimal function with stimulation techniques,” she said. “We hope that our novel finding on the neural origin of beta will help guide research to manipulate beta, and possibly other rhythms, for improved function in sensorimotor pathologies.”

A giant eyeball from a mysterious sea creature was found by a man walking the beach in Pompano Beach on Wednesday. Wildlife officials said it likely came from a swordfish but experts mused that it likely came from a giant squid, whale or large fish. (Source)

Why Number Are The Way They Are

New York City Has Genetically Distinct ‘Uptown’ and ‘Downtown’ Rats

A graduate student sequenced rats all over Manhattan, and discovered how the city affects their genetic diversity.

whoa-o-o-o-o-oh-oh

WHOA-O-O-O-O-OH-OH

UPTOWN RAT

After 20 years in space, the Cassini spacecraft is running out of fuel. In 2010, Cassini began a seven-year mission extension in which the plan was to expend all of the spacecraft’s propellant exploring Saturn and its moons. This led to the Grand Finale and ends with a plunge into the planet’s atmosphere at 6:32 a.m. EDT on Friday, Sept. 15.

The spacecraft will ram through Saturn’s atmosphere at four times the speed of a re-entry vehicle entering Earth’s atmosphere, and Cassini has no heat shield. So temperatures around the spacecraft will increase by 30-to-100 times per minute, and every component of the spacecraft will disintegrate over the next couple of minutes…

Cassini’s gold-colored multi-layer insulation blankets will char and break apart, and then the spacecraft’s carbon fiber epoxy structures, such as the 11-foot (3-meter) wide high-gain antenna and the 30-foot (11-meter) long magnetometer boom, will weaken and break apart. Components mounted on the outside of the central body of the spacecraft will then break apart, followed by the leading face of the spacecraft itself.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Your body is an incredibly bizarre machine.

“What you see is a myosin protein dragging an endorphin along a filament to the inner part of the brain’s parietal cortex which creates happiness. Happiness. You’re looking at happiness.”

After the Battle of Shiloh in 1862, many Civil War soldiers’ lives were saved by a phenomenon called ‘Angel’s Glow.’ The soldiers, who lay in the mud for two rainy days, had wounds that began to glow in the dark and heal unusually fast. In 2001, 2 teens won an international science fair by discovering the soldiers had been so cold that their bodies created the perfect conditions for growing a bioluminescent bacteria, which ultimately destroyed the bad bacteria that could’ve killed them. Source Source 2 Source 3

Some intriguing exoplanets

An exoplanet or extrasolar planet is a planet that orbits a star other than the Sun. The first scientific detection of an exoplanet was in 1988. However, the first confirmed detection came in 1992; since then, and as of 1 April 2017, there have been 3,607 exoplanets discovered in 2,701 planetary systems and 610 multiple planetary systems confirmed.

1- Kepler-186f

was the first rocky planet to be found within the habitable zone – the region around the host star where the temperature is right for liquid water. This planet is also very close in size to Earth. Even though we may not find out what’s going on at the surface of this planet anytime soon, it’s a strong reminder of why new technologies are being developed that will enable scientists to get a closer look at distant worlds.

2- CoRoT 7b

The first super-Earth identified as a rocky exoplanet, this planet proved that worlds like the Earth were indeed possible and that the search for potentially habitable worlds (rocky planets in the habitable zone) might be fruitful.

3- Kepler-22b  

A planet in the habitable zone and a possible water-world planet unlike any seen in our solar system.

4- Kepler 10-b

Kepler’s first rocky planet discovery is a scorched, Earth-size world that scientists believe may have a lava ocean on its surface.

5- 55 Cancri e

55 Cancri e is a toasty world that rushes around its star every 18 hours. It orbits so closely – about 25 times closer than Mercury is to our sun – that it is tidally locked with one face forever blisters under the heat of its sun. The planet is proposed to have a rocky core surrounded by a layer of water in a “supercritical” state, where it is both liquid and gas, and then the whole planet is thought to be topped by a blanket of steam.

6- 51 Pegasi b

This giant planet, which is about half the mass of Jupiter and orbits its star every four days, was the first confirmed exoplanet around a sun-like star, a discovery that launched a whole new field of exploration.

7- Kepler-444 system

The oldest known planetary system has five terrestrial-sized planets, all in orbital resonance. This weird group showed that solar systems have formed and lived in our galaxy for nearly its entire existence.

8- PSR B1257+12 system

Discovered in 1992 and 1994, the planets that orbit pulsar PSR B1257+12 are not only the smallest planetary bodies known to exist outside our solar system, they also orbit a neutron star. These weird “pulsar planets” demonstrated that planets exist in all environments in the galaxy – even around the remnants of an exploded star.

9- HD 80606 b  

This world has the most eccentric orbit, and as one scientist put it, “wears its heart on its sleeve,” with storms, rotation, atmospheric heating, and a crazy orbit all plainly visible.

10- OGLE-2005-BLG-390

Considered to be the first cold super Earth, this exoplanet began to form a Jupiter-like core of rock and ice, but couldn’t grow fast enough in size. Its final mass is five times that of Earth. The planet’s nickname is Hoth, after a planet from Star War

Credits: NASA / JPL-Caltech