Mr. Mattiewis Dubaj

tearingdowndoors: luke Photographer

Tue, 21 May 2013 17:07:34 -0400

luke Photographer

sciencenote: The Doppler effect is observed whenever the source...

Tue, 21 May 2013 17:07:14 -0400

The Doppler effect is observed whenever the source of waves is moving with respect to an observer. The Doppler effect can be described as the effect produced by a moving source of waves in which there is an apparent upward shift in frequency for observers towards whom the source is approaching and an apparent downward shift in frequency for observers from whom the source is receding. It is important to note that the effect does not result because of an actual change in the frequency of the source. Using the example above, the bug is still producing disturbances at a rate of 2 disturbances per second; it just appears to the observer whom the bug is approaching that the disturbances are being produced at a frequency greater than 2 disturbances/second. The effect is only observed because the distance between observer B and the bug is decreasing and the distance between observer A and the bug is increasing.

The Dopplereffect can be observed for any type of wave - water wave, sound wave, light wave, etc. We are most familiar with the Dopplereffect because of our experiences with sound waves. Perhaps you recall an instance in which a police car or emergency vehicle was traveling towards you on the highway. As the car approached with its siren blasting, the pitch of the siren sound (a measure of the siren’s frequency) was high; and then suddenly after the car passed by, the pitch of the siren sound was low. That was the Dopplereffect - an apparent shift in frequency for a sound wave produced by a moving source.

Photo

Tue, 21 May 2013 17:04:41 -0400

jtotheizzoe: ES from SCNT: Another Human Stem Cell...

Tue, 21 May 2013 17:02:40 -0400

jtotheizzoe:

ES from SCNT: Another Human Stem Cell Milestone

Human embryonic stem cells have been created using a technique called somatic cell nuclear transfer (SCNT) for the first time. Interestingly, SCNT might be the oldest genetic reprogramming technology in our biological arsenal, but its use in creating human ES cells has proven elusive.

We’ll get to the news in a moment, but first some history. In 1958, John Gurdon made a frog from a tadpole.

“Congratulations, John, that’s how frogs are usually made. Big whoop.”

Except that he did it by inserting the nucleus from a tadpole cell into a frog egg that had its own nucleus removed. It should have been immediately clear to everyone how cool this was, but it took 54 years for him to get the Nobel Prize, which he shared in 2012 with some other stem cell reprogramming pioneers.

Why did that work? It makes perfect sense when you think about the job of an egg. Compared to sperm cells, eggs are huge. They are Death Stars and sperm are X-wings, each looking for an exhaust port into which they can shove their half of the genetic material. The egg is stuffed full of the proteins, mRNAs and other biological machinery that it will need to hit the ground running and begin the process of development. In other words the sperm just brings genes to the party (there’s a joke in there somewhere). The egg is the pilot, engineer and tech support. (For the genetics fans out there, this is also why maternal effects exist)

In a sense, the egg is a big bag of stuff that will define what the embryo is, at least for the first several cell divisions. Somewhere in all that eggy cytoplasm is a set of factors that are primed and ready to lead the way to embryoville.

Wait … where were we again? Oh yeah: Human stem cells.

So while SCNT technology has been around for a while (and has been used to create some very famous sheep), it never worked in humans (despite a faked claim in 2005). The process of removing and replacing the nucleus of donated human eggs was too disruptive. Until the new report in Cell last week.

Using donated eggs (obtained by consenting women from certfied IVF clinics) robbed of their own nucleus, a whole skin cell was injected and given an electric shock to stimulate cell division. That that even works is amazing. But the harvested stem cells acted like normal ES cells, and appear to be just as useful. They can be used to create patient-matched cells to study specific diseases in the petri dish, or engineered into neurons and other tissues to implant into a donor’s own body. All without destroying embryos.

Of course, we can already make near-embryonic stem cells by directly reprogramming skin cells with a simple genetic cocktail. So does it make sense to seek out egg donations for a technology like this? The ethics of making an economy out of egg donation are murky. And of course, there’s the worry that instead of just being used for making stem cells, it could be used to clone an entire human. That’s completely illegal, but it’s worth considering, at least.

It’s a new step forward in our ability to understand and manipulate human biology, and the advancement of knowledge like this is always worthy of excitement. Look at what power we hold! But we are men and women, not gods … and that’s what makes this all the more remarkable.

bringmetheheadofdaviddixon: (via you don’t have to capture my...

Tue, 21 May 2013 17:02:02 -0400

bringmetheheadofdaviddixon:

(via you don’t have to capture my essence | Bring Me the Head of David Dixon)

Please click on the image to view the full animation.

incoffins: this is like a $100 card too

Tue, 21 May 2013 00:42:13 -0400

incoffins:

this is like a $100 card too

NGC3584 (narrowband) in Carina. — Desert Hollow Observatory

Tue, 21 May 2013 00:40:31 -0400

NGC3584 (narrowband) in Carina. — Desert Hollow Observatory

31262: Shuttle Enterprise in launch configuration at Vandenberg...

Tue, 21 May 2013 00:40:04 -0400

31262:

Shuttle Enterprise in launch configuration at Vandenberg AFB.

Photo

Tue, 21 May 2013 00:39:19 -0400

vlynx: Camille Seaman

Tue, 21 May 2013 00:36:39 -0400

vlynx:

Camille Seaman

jtotheizzoe: Our Atmosphere is Escaping! Oh gahd! Quick! Take...

Mon, 20 May 2013 18:17:50 -0400

jtotheizzoe:

Our Atmosphere is Escaping!

Oh gahd! Quick! Take a deep breath!! Someone save Minute Earth!!!

What’s that? Oh … we have nothing to worry about? It’s only losing hydrogen and helium? And it will take billions of years to lose that stuff? Whew.

Bonus: Check out my YouTube vid about just how small (and shared) our atmosphere really is.

Photo

Fri, 17 May 2013 21:39:38 -0400

helenalongphotoworks: photo by helena long

Fri, 17 May 2013 18:46:54 -0400

helenalongphotoworks:

photo by helena long

dondianda: Celestial Evening

Fri, 17 May 2013 18:45:56 -0400

dondianda:

Celestial Evening

crookedindifference: The first image obtained from a GOES...

Fri, 17 May 2013 18:35:36 -0400

crookedindifference:

The first image obtained from a GOES satellite (1975, October 25 16:45GMT)

michaeloneal: Mt. Davidson 3.16.13

Fri, 17 May 2013 16:55:49 -0400

michaeloneal:

Mt. Davidson 3.16.13

sh4rkies: Black Swan & kois 黑天鵝 & 錦鯉 »» Melinda

Fri, 17 May 2013 16:34:55 -0400

sh4rkies:

Black Swan & kois 黑天鵝 & 錦鯉 »» Melinda

wah-mos: who has desktops anymore GET WITH IT

Fri, 17 May 2013 16:33:12 -0400

wah-mos:

who has desktops anymore GET WITH IT

Photo

Fri, 17 May 2013 16:01:11 -0400

tentativeundertaker: thehotelcat: housewarningparty: cheersfor...

Thu, 16 May 2013 23:56:00 -0400

tentativeundertaker:

thehotelcat:

housewarningparty:

cheersfortacos:

ontheupandup:

vinyasanya:

its never not a good time for this video

I really want this to get to 100000 notes

yes

the first time i saw this video was in like 7th grade and it was filmed right by my friends house by these two kids we saw all the time and we had the biggest crushes on them A TRUE STORY FROM ME

I just love the lady in the grocery store that points back

ITS COOL GUY