when your friend finds an old study guide for one of your finals

medschoolapplicant:

image

victoriousvocabulary:

ILLUMINANCE
[noun]
1. an act or instance of illuminating; to supply or brighten with light.
2. intellectual or spiritual enlightenment.
3. Photometry: the total luminous flux, i.e. the measure of the perceived power of light incident on a surface, per unit area.
Etymology: from Latin illuminatus, past participle of illūmināre, “to light up, brighten”.
[Amanda Sage]

victoriousvocabulary:

ILLUMINANCE

[noun]

1. an act or instance of illuminating; to supply or brighten with light.

2. intellectual or spiritual enlightenment.

3. Photometry: the total luminous flux, i.e. the measure of the perceived power of light incident on a surface, per unit area.

Etymology: from Latin illuminatus, past participle of illūmināre, “to light up, brighten”.

[Amanda Sage]

Tags: word

neurosciencestuff:

Existence of new neuron repair pathway discovered
Most of your neurons can’t be replaced.
Other parts of your body – such as skin and bone – can be replaced by the body growing new cells, but when you injure your neurons, you can’t just grow new ones; instead, the existing cells have to repair themselves.
In the case of axon injury, the neuron is able to repair or sometimes even fully regenerate its axon. But neurons have two sides – the axon (which sends signals to other cells) and the dendrite (which receives signals from other cells).
Melissa Rolls, an associate professor of biochemistry and molecular biology at Penn State and director of the Huck Institutes’ Center for Cellular Dynamics, has done extensive comparisons of axons and dendrites – culminating recently in a paper published in Cell Reports.
“We know that the axon side can repair itself,” says Rolls, “and we know a bunch of the molecular players. But we really didn’t know whether neurons have the same capacity to regenerate their dendrites, and so that’s what we set out to find in this study.”
“Our lab uses a Drosophila model system, where the dendrites are very accessible to manipulation,” she says, “so we decided that we would start by removing all the dendrites from the neurons to see if they could regenerate. We didn’t start with anything subtle, like taking off just a few dendrites. We said ‘Let’s just push the system to its maximum and see if this is even possible.’ And we were surprised because we found that not only is it possible, it’s actually much faster than axon regeneration: at least in the cells that we’re using, axon regeneration takes a day or two to initiate, while dendrite regeneration typically initiates within four to six hours and it works really well. All the cells where we removed the dendrites grew new dendrites – none of them died; so it’s clear that these cells have a way to both detect dendrite injury and initiate regrowth of the injured part.”
Read more

neurosciencestuff:

Existence of new neuron repair pathway discovered

Most of your neurons can’t be replaced.

Other parts of your body – such as skin and bone – can be replaced by the body growing new cells, but when you injure your neurons, you can’t just grow new ones; instead, the existing cells have to repair themselves.

In the case of axon injury, the neuron is able to repair or sometimes even fully regenerate its axon. But neurons have two sides – the axon (which sends signals to other cells) and the dendrite (which receives signals from other cells).

Melissa Rolls, an associate professor of biochemistry and molecular biology at Penn State and director of the Huck Institutes’ Center for Cellular Dynamics, has done extensive comparisons of axons and dendrites – culminating recently in a paper published in Cell Reports.

“We know that the axon side can repair itself,” says Rolls, “and we know a bunch of the molecular players. But we really didn’t know whether neurons have the same capacity to regenerate their dendrites, and so that’s what we set out to find in this study.”

“Our lab uses a Drosophila model system, where the dendrites are very accessible to manipulation,” she says, “so we decided that we would start by removing all the dendrites from the neurons to see if they could regenerate. We didn’t start with anything subtle, like taking off just a few dendrites. We said ‘Let’s just push the system to its maximum and see if this is even possible.’ And we were surprised because we found that not only is it possible, it’s actually much faster than axon regeneration: at least in the cells that we’re using, axon regeneration takes a day or two to initiate, while dendrite regeneration typically initiates within four to six hours and it works really well. All the cells where we removed the dendrites grew new dendrites – none of them died; so it’s clear that these cells have a way to both detect dendrite injury and initiate regrowth of the injured part.”

Read more

the-writers-ramblings:

tv tropes + lotr

↳ character tropes: boromir

(via hobbits-of-hobbiton)

brobdingnagianpseudonym:

Swedish woman finds 2,000-year-old gold ring - The Local

paprikapotts:

barbaricyip:

motherfuckingnazgul:

shireen-baratheon:

#THERE ARE LITERALLY THREE MOVIES AND A HUGE-ASS BOOK EXPLAINING WHY KEEPING IT IS A BAD IDEA

"…it felt like a gift from the underworld," Lundin told The Local. "It was my magnificent ring. I didn’t want to give it up."

O_O

image

(via hobbits-of-hobbiton)

Maisie Williams reacting fact that “selfie” was chosen as Oxford’s word 2013

(Source: brandon-starks, via hobbits-of-hobbiton)

jtotheizzoe:

A message about forgotten diseases, and how we can keep them forgotten (hint: vaccines) from Beatrice the Biologist, whose comics are wonderful.

Do it for the testicles. And for the ovaries. And for the good of humanity.

(via uaortho)

neurosciencestuff:

Why your nose can be a pathfinder
When I was a child I used to sit in my grandfather’s workshop, playing with wood shavings. Freshly shaven wood has a distinct smell of childhood happiness, and whenever I get a whiff of that scent my brain immediately conjures up images of my grandfather at his working bench, the heat from the fireplace and the dog next to it.
Researchers at the Kavli Institute for Systems Neuroscience have recently discovered the process behind this phenomenon. The brain, it turns out, connects smells to memories through an associative process where neural networks are linked through synchronised brain waves of 20-40 Hz.
– We all know that smell is connected to memories, Kei Igarashi, lead author, explains.– We know that neurons in different brain regions need to oscillate in synchrony for these regions to speak effectively to each other. Still, the relationship between interregional coupling and formation of memory traces has remained poorly understood. So we designed a task to investigate how odour-place representation evolved in the entorhinal and hippocampal region, to figure out whether learning depends on coupling of oscillatory networks.
Smell guides the way in maze The researchers designed a maze for rats, where a rat would see a hole to poke its nose into. When poking into the hole, the rat was presented with one of two alternative smells. One smell told the rat that food would be found in the left food cup behind the rat. The other smell told it that there was food in the right cup. The rat would soon learn which smell would lead to a reward where. After three weeks of training, the rats chose correctly on more than 85% of the trials. In order to see what happened inside the brain during acquisition, 16–20 electrode pairs were inserted in the hippocampus and in different areas of the entorhinal cortex.
After the associations between smell and place were well established, the researchers could see a pattern of brain wave activity (the electrical signal from a large number of neurons) during retrieval.
Coherent brain activity evolves with learning – Immediately after the rat is exposed to the smell there is a burst in activity of 20–40 Hz waves in a specific connection between an area in the entorhinal cortex, lateral entorhinal cortex (LEC), and an area in the hippocampus, distal CA1 (dCA1), while a similar strong response was not observed in other connections, Igarashi explains.
This coherence of 20–40 Hz activity in the LEC and dCA1 evolved in parallel with learning, with little coherence between these areas before training started. By the time the learning period was over, cells were phase locked to the oscillation and a large portion of the cells responded specifically to one or the other of the smell-odour pairs.
Long distance communication in brain mediated by waves – This is not the first time we observe that the brain uses synchronised wave activity to establish network connections, Edvard Moser, director of the Kavli Institute for Systems Neuroscience says. – Both during encoding and retrieval of declarative memories there is an interaction between these areas mediated through gamma and theta oscillations. However, this is the first study to relate the development of a specific band of oscillations to memory performance in the hippocampus. Together, the evidence is now piling up and pointing in the direction of cortical oscillations as a general mechanism for mediating interactions among functionally specialised neurons in distributed brain circuits.
So, there you have it – the signals from your nose translate and connect to memories in an orchestrated symphony of signals in your head. Each of these memories connects to a location, pinpointed on your inner map. So when you feel a wave of reminiscence triggered by a fragrance, think about how waves created this connection in the first place.

neurosciencestuff:

Why your nose can be a pathfinder

When I was a child I used to sit in my grandfather’s workshop, playing with wood shavings. Freshly shaven wood has a distinct smell of childhood happiness, and whenever I get a whiff of that scent my brain immediately conjures up images of my grandfather at his working bench, the heat from the fireplace and the dog next to it.

Researchers at the Kavli Institute for Systems Neuroscience have recently discovered the process behind this phenomenon. The brain, it turns out, connects smells to memories through an associative process where neural networks are linked through synchronised brain waves of 20-40 Hz.

– We all know that smell is connected to memories, Kei Igarashi, lead author, explains.– We know that neurons in different brain regions need to oscillate in synchrony for these regions to speak effectively to each other. Still, the relationship between interregional coupling and formation of memory traces has remained poorly understood. So we designed a task to investigate how odour-place representation evolved in the entorhinal and hippocampal region, to figure out whether learning depends on coupling of oscillatory networks.

Smell guides the way in maze
The researchers designed a maze for rats, where a rat would see a hole to poke its nose into. When poking into the hole, the rat was presented with one of two alternative smells. One smell told the rat that food would be found in the left food cup behind the rat. The other smell told it that there was food in the right cup. The rat would soon learn which smell would lead to a reward where. After three weeks of training, the rats chose correctly on more than 85% of the trials. In order to see what happened inside the brain during acquisition, 16–20 electrode pairs were inserted in the hippocampus and in different areas of the entorhinal cortex.

After the associations between smell and place were well established, the researchers could see a pattern of brain wave activity (the electrical signal from a large number of neurons) during retrieval.

Coherent brain activity evolves with learning
– Immediately after the rat is exposed to the smell there is a burst in activity of 20–40 Hz waves in a specific connection between an area in the entorhinal cortex, lateral entorhinal cortex (LEC), and an area in the hippocampus, distal CA1 (dCA1), while a similar strong response was not observed in other connections, Igarashi explains.

This coherence of 20–40 Hz activity in the LEC and dCA1 evolved in parallel with learning, with little coherence between these areas before training started. By the time the learning period was over, cells were phase locked to the oscillation and a large portion of the cells responded specifically to one or the other of the smell-odour pairs.

Long distance communication in brain mediated by waves
– This is not the first time we observe that the brain uses synchronised wave activity to establish network connections, Edvard Moser, director of the Kavli Institute for Systems Neuroscience says. – Both during encoding and retrieval of declarative memories there is an interaction between these areas mediated through gamma and theta oscillations. However, this is the first study to relate the development of a specific band of oscillations to memory performance in the hippocampus. Together, the evidence is now piling up and pointing in the direction of cortical oscillations as a general mechanism for mediating interactions among functionally specialised neurons in distributed brain circuits.

So, there you have it – the signals from your nose translate and connect to memories in an orchestrated symphony of signals in your head. Each of these memories connects to a location, pinpointed on your inner map. So when you feel a wave of reminiscence triggered by a fragrance, think about how waves created this connection in the first place.

theyuniversity:

Thanks. ╚(ಠ_ಠ)╝
(Source: imgur)

theyuniversity:

Thanks. ╚(ಠ_ಠ)╝

(Source: imgur)

(via sconesetpetitfourebiscotti)

who-:

Located near the Red Sea in El Gouna, Egypt, Desert Breath is an impossibly immense land art installation dug into the sands of the Sahara desert by the D.A.ST. Arteam back in 1997. The artwork was a collaborative effort spanning two years between installation artist Danae Stratou, industrial designer Alexandra Stratou, and architect Stella Constantinides, and was meant as an exploration of infinity against the backdrop of the largest African desert. Covering an area of about 1 million square feet (100,000 square meters) the piece involved the displacement of 280,000 square feet (8,000 square meters) of sand and the creation of a large central pool of water.

daehnerys:

The king and his men
stole the queen from her bed,
and bound her in her bones.
The seas be ours, and by the powers;
where we will, we’ll roam.

(via ampersand-et)

neurosciencestuff:

Improved thinking. Decreased appetite. Lowered blood pressure. The potential health benefits of dark chocolate keep piling up, and scientists are now homing in on what ingredients in chocolate might help prevent obesity, as well as type-2 diabetes. They found that one particular type of antioxidant in cocoa prevented laboratory mice from gaining excess weight and lowered their blood sugar levels. The report appears in ACS’ Journal of Agricultural & Food Chemistry.

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Andrew P. Neilson and colleagues explain that cocoa, the basic ingredient of chocolate, is one of the most flavanol-rich foods around. That’s good for chocolate lovers because previous research has shown that flavanols in other foods such as grapes and tea can help fight weight gain and type-2 diabetes. But not all flavanols, which are a type of antioxidant, are created equal. Cocoa has several different kinds of these compounds, so Neilson’s team decided to tease them apart and test each individually for health benefits.

The scientists fed groups of mice different diets, including high-fat and low-fat diets, and high-fat diets supplemented with different kinds of flavanols. They found that adding one particular set of these compounds, known as oligomeric procyanidins (PCs), to the food made the biggest difference in keeping the mice’s weight down if they were on high-fat diets. They also improved glucose tolerance, which could potentially help prevent type-2 diabetes. “Oligomeric PCs appear to possess the greatest antiobesity and antidiabetic bioactivities of the flavanols in cocoa, particularly at the low doses employed for the present study,” the researchers state.

 

(Source: acs.org)