the guide book of misc notes

hey! do your homework! if you don't get it, we'd probably have something around here that could help you. maybe.

[adversariabaedeker-blog]

A really useful website! Great for lazy students like me

[neurolove]

[medicalschool]

Recently, someone asked me to talk about Neurotransmitters, so I am going to go back to the basics as to how neurons work, what action potentials are, how they happen, and then what neurotransmitters are and what different ones may do! 

Let’s begin to talk action potentials.  Action potentials are how messages are carried from one neuron to the next.  Neurons are specialized for this kind of signal because they have excitable membranes.  This can be pretty hard to grasp, but essentially, they use specialized ion channels (things small molecules can move through) to send an electrical current down the length of the axon.

Action potentials are able to happen because the cell is kept more negative than the outside by having a larger amount of potassium (K+) inside the cell and larger amounts of sodium (Na+) outside the cell.  This gradient, or difference in the concentrations inside and outside the cell, are created by the Na-K pump.  These are like cell membrane club bouncers that push the K+ (hot girls) inside the cell (club) and push the Na+ (wasted people) outside the cell.  If this analogy doesn’t work for you, then just try to get it from the basic science standpoint.

So you have the Na-K pump that keeps more K+ inside and more Na+ outside.  To do this, it uses energy, known as ATP.  Therefore, you might sometimes hear this referred to as a Na-K ATPase pump, simply meaning it uses ATP to work.

[Image Source]

[adversariabaedeker-blog]

Flashcards in the form of Powerpoint slides I made for Chapter 4 of Form 4 Biology. I'll upload the rest of the subtopics when I'm done!

[the-science-llama]

Closest Star System Found in a Century

Say hello to our new neighbors.

The star system is named “WISE J104915.57-531906″ because it was discovered in a map of the entire sky obtained by the NASA-funded Wide-field Infrared Survey Explorer (WISE) satellite. It is only slightly farther away than the second-closest star, Barnard’s star, which was discovered 6.0 light years from the Sun in 1916. The closest star system consists of Alpha Centauri, found to be a neighbor of the Sun in 1839 at 4.4 light years, and the fainter Proxima Centauri, discovered in 1917 at 4.2 light years.

First question, how did we miss this?

The new system is a binary system of brown dwarfs which are stars that are too small in mass to ever become hot enough to ignite hydrogen fusion. As a result, they are very cool and dim, resembling a giant planet like Jupiter more than a bright star like the sun. Oh that’s how we missed it.

Via NASA, Earthsky

[physicsphysics]

Clever physics tees - available at thenerdiestshirts

[science-junkie]

Rhythms of starlight, melodies of astrophysics

Ever wondered what the music of the cosmos sounds like? You’re about to find out. Astrophysicist and TED Senior Fellow Lucianne Walkowicz works on the Kepler mission, looking at a patch of our galaxy to learn about stars and their planets. Here, she tells us how this is done:

Stars periodically appear brighter and darker on their own because they have bright and dark patches on their surfaces caused by the star’s magnetic field. As it spins, we see light fluctuate as the patches rotate into and out of view – and the frequency of the fluctuation tells us how fast it’s spinning. To make things a bit more complicated, stars don’t rotate exactly like tops, in that different latitudes on the star spin at different rates – so usually there are several frequencies in the star’s light, and they can change and drift in time. I take the data and search for which frequencies are present at different times, then scale them to frequencies the human ear can hear, using a sine-wave generator. Then I create tones that change with time to represent how the frequencies in the star are changing. A first pass sounds like this: in each second of playback, you hear the three strongest frequencies in the star for a day of real time. As you listen, the sounds change as the frequencies change. Then I do some additional processing to get the effect I want. Usually I want to capture some echo to convey a sense of vast space, and some blending between notes to convey the dynamic nature of the features on the star’s surface that are creating the changes in the star’s light. In Powerful Protectors I’ve woven the sounds of two stars in with samples of Buddhist chanting around the world. The composition is about how people try to access deeper knowledge about our universe.

Source: ted.com

[vasuki-blog]

Manipulating Water with Sound

[oyster-and-pearl-deactivated201]

SCIENCE

[biocanvas]

The eyes of a jumping spider (shown here is a section through the head) have distinct functions. The large central eyes provide a high-resolution, three-dimensional view in order to estimate the location of prey, while the smaller eyes on the side offer a wider field of vision to respond to threats.

Image by Dr. Igor Siwanowicz, Max Planck Institute of Neurobiology.

[climateadaptation-deactivated20]

I know, to most of you this is basic stuff. But sometimes it is good to revisit the basics. I like the part about confirmation bias, which I and my fellow enviros fall for all the time…

You know how to tell if something controversial is actually true, but what if you want to read up on something without stumbling into half-truths and pseudoscience? Here’s how to use the internet as a powerful research tool without being led astray.

Your two biggest enemies: 

Your own confirmation bias.Confirmation bias is your own natural tendency to find, believe, and source information that agrees with (or confirms) your already-held opinions about a topic. It’s a problem even for highly educated scientists and experts in their field, and it’s something you’ll need to be ready to battle when you’re looking into a topic that’s new to you. You may be presented with information that’ll challenge your preconceived notions and beliefs. Keep an open mind and seek to understand and find evidence to all sides of an argument (especially the ones you disagree with.) For more on confirmation bias, read this excellent article on the topic. 

Questionable sources of information. The only thing worse than confirmation bias are trapped in unsourced, poorly-cited articles that draw conclusions without backing them up. Even the best do this sometimes, like citing a study that doesn’t support their conclusions or reporting a study’s conclusions blindly. Keep an eye out though, even poorly-cited work can lead you to valuable reading, but unsourced conjecture should be treated as opinion.

Read the rest of the tips at LifeHacker.

It’s Climate Science Communications Week at Climate Adaptation!   For the entire week of Feb. 18 - 23, I’ll cover how climate change is discussed by the media, scientists, researchers, academics, and politicians. If you have sources or ideas on communicating climate change, send to: http://climateadaptation.tumblr.com/submit

[medicalschool]

Anatomy of the Human Heart

[throughascientificlens]

Cholesterol

This fascinating molecule plays a rather important role in your body, maybe more so than you realised. Cholesterol tests are something we’re aware of, but what actually happens when our cholesterol is too high? Or too low, for that matter?

Every one of our cells is bound by a membrane and this membrane plays an important role of maintaining concentration gradients of chemicals among other things. It is important that this membrane be fluid so that proteins and lipids embedded within the membrane can move around to facilitate transport across the membrane and various other functions.

Cholesterol plays an important role in maintaining fluidity of the membrane. Cholesterol embeds itself in the membrane and proceeds to aid in making the membrane a little more firm. Without cholesterol the membrane would be far too fluid and your membranes would turn to mush, but with too much cholesterol your membranes would harden and you would no loner be able to maintain concentration gradients of such nutrients as Ca2+ and K+. If this could instantaneously happen to you, you would feel an anesthetic-like feeling and then quickly lose consciousness and die.

What we can learn from this is: everything in moderation.

Images courtesy of Wikimedia

[scienceisbeauty]

Cells - Structure and Function (University of Illinois)

[mediagrams]

Outer, inner and middle ear

[likeamagpie]

[rabbitinthemoon-blog]

The mind is beautiful because of the paradox. It uses itself to understand itself.

Adam Elenbass  (via mindovermatterzine)

[cheese24k]

I would have aced biology if the teachers all taught the course like the narrator

[adversariabaedeker-blog]

F4 Biology - Double Membrane Organelles Part 2

Sorry for the delay, my friends. Here's the part 2 of our double membrane organelles! 3. Nucleus Back in the lower form, all we see of our dear little nucleus is a dark circle thing in the middle of our animal and plant cells. It's like an egg yolk, right? Now, we're going to increase our magnification and see what's beyond the little nut. As you can see, it's a dense, large and spherical organelle, hence the dark colour. The nucleus consists of a) the nuclear envelope, which separates the contents of the nucleus from the cytoplasm, b) chromatin, which carries genetic material in the form of DNA, which determines the characteristics and the functions of the cell. Just so you know, chromatin is the form chromosomes take when the cell is not dividing. Lastly, c) a darker and dense region called the nucleolus. Like what we've learnt for the last three years, the nucleus acts as a brain for your cell. The DNA controls ALL activities. One of the examples would be the protein synthesis carried out by the ribosomes which is regulated by the coded information contained in the chromosomes. We out!