>“Both these studies suggest that the IOM underestimated the requirement substantially,” said Garland. “The error has broad implications for public health regarding disease prevention and achieving the stated goal of ensuring that the whole population has enough vitamin D to maintain bone health.”
>The recommended intake of vitamin D specified by the IOM is 600 IU/day through age 70 years, and 800 IU/day for older ages. “Calculations by us and other researchers have shown that these doses are only about one-tenth those needed to cut incidence of diseases related to vitamin D deficiency,” Garland explained.
>Robert Heaney, M.D., of Creighton University wrote: "We call for the NAS-IOM and all public health authorities concerned with transmitting accurate nutritional information to the public to designate, as the RDA, a value of approximately 7,000 IU/day from all sources.”
>“This intake is well below the upper level intake specified by IOM as safe for teens and adults, 10,000 IU/day,” Garland said. Other authors were C. Baggerly and C. French, of GrassrootsHealth, a voluntary organization in San Diego CA, and E.D. Gorham, Ph.D., of UC San Diego.
Everything we know about skin color suggests light skin is an adaptation to a diet poor in vitamin D
Skin cancer isn't an issue for people who rarely live to see their 30s
Very interesting, although that doesn't mean darker skinned people cannot produce vitamin D through UV light. Especially since it is very hard if not impossible to acquire 7-10k IDU's of vitamin D from diet alone. Or even close to that. The best you can get is about 450 IDU's from 3 ounces of food and that is a sockeye salmon fillet. No other food source seems to have a higher density of vitamin D. So in short we need to get vitamin D though UV light or supplementation for acquiring enough vitamin D through diet is almost neigh impossible.
That used to be the most suggested theory, but I was actually doing some light research on the subject a few months ago out of curiosity, and found that it's probably a bit more complicated matter than we thought.
I don't recall exactly what I read, but basically skin pigmentation prevents destruction of folate (the lack of which can cause severe birth defects, a much stronger evolutionary pressure than sunburn resistance or getting a cancer that would occur after the typical lifespan of a human in wilderness conditions) in the skin by UV rays. Pigmented skin is also thicker and a much better barrier against water loss and other environmental hazards, which is important in hairless animals like us.
The current suggested reason why some white northerners make more vitamin D is because they have a mutation that results in less or no filaggrin in the skin, which ultimately translates into more UV-B absorbed because of body chemistry I don't understand or remember.
The evolutionary pressure for white skin may simply be that pigmented skin has a metabolic cost that those in the far north couldn't afford. I'm less convinced on this part.
That's what I came across at the time anyways.
Skin color is based on region. Where there is more or less sunlight. Northern Europe having less sunlight, so people there have thinner skin to absorb more Vitamin D. If an African man/woman were to move to Scandinavia, they would end up with Rickets from the lack of sunlight. Point is, if you are getting Rickets, take Vitamin D.
My Mexican forearms can attest to this.
We have officially bypassed the blood brain barrier... in mice.
>According to the researchers, “each time the magnetic moments of the [magnetic nanoparticles] align with the alternating direction of the [radiofrequency] field, they release this energy once they relax back to their original direction.” The heat emitted by the magnetic nanoparticles made the BBB more permeable for a brief period—long enough to let some dye bonded to the nanoparticles slip through.
Europe is famously tesselated, with different cultural and language groups clustering in different regions.
But how did they all get there?
And how are they related?
One way of answering these questions comes from digging up relics of the past.Europe has a rich archaeological record, ranging from periods well before the famous metal ages (i.e. copper, bronze and iron) to the recent adventures of the Romans, Vandals, Huns and Vikings.
Distinctive types of pottery and cultural practices associated with burials and settlements have been used to group the ancient populations into individual "archaeological cultures". However, it hasn't been clear whether there is a genetic basis for these group boundaries or whether they're just cultural.
Another line of evidence to illuminate how various groups are related comes from their languages. There is the well known Indo-European language tree – ranging from Hindi to Russian to Spanish. But it's also quite unclear how the languages spread to their present regions.
Now we have another layer of information to help us reveal the history of European peoples: DNA sequencing.
Along with our colleagues, we have been using genome sequencing technology to analyse the vast array of ancient skeletons recovered from across Europe, ranging from the original hunter-gatherer inhabitants to the first farmers who appear around 8,000 years ago, and right up to the early Bronze Age 3,500 years ago.
Message too long. Click here to view the full text.
Because I'm in the mood.
Aircraft! Airpower. Air dominance. Modern war has changed in ways largely unrecognizable to our ancestors by the sheer virtue of this aspect alone. Ever since the days of the Red Baron shooting down Camels with a 12 gauge, militaries around the world have sought out a means of putting to an end that pesky happenstance of a fellow from the other side dropping bullets or bombs on them from a decidedly unfair position of three-dimensional advantage.
Welcome to the Acid Man SAM thread. You are, as always, invited to
In the early days of aerial warfare, when warplanes had evolved beyond a modestly useful curiosity and become one of the key defining aspects of victory (no ground victory without air supremacy!) we made do with large caliber guns and explosive, fragmenting warheads. "Flak." Explosive shells had timed fuses that would cause them to burst at the measured altitude of the slow moving enemy planes, with the resulting clouds of shrapnel, or flak, hopefully damaging critical systems and/or killing the crew of the aircraft.
Since this thread mostly concerns SAMs, we're only going to be looking at AAA in one real aspect that was carried over into missile development: The radar proximity fuse. Or as it was originally called for the purposes of counterintelligence, the VT, or "variable time" fuse.
Buckle up, OPchan. We're about to experience some turbulence. The SAM thread is GO!
Care to link to references about RDX or NC+NG composite rocket propellant used in military munitions as the propellant?
Ammonium perchlorate composites are used in modern munitions, including air-to-air missiles.
Do include more info. This stuff is interesting.
I'll have to take a better look at those radar triggers. Sounds surprisingly simple.
I've lost the original links in my mountain of sources, but here's some stuff from some text files I saved.
>Higher-performance solid rocket propellants are used in large strategic missiles (as opposed to commercial launch vehicles). HMX, C4H8N4(NO2)4, a nitramine with greater energy than ammonium perchlorate, is the main ingredient in NEPE-75 propellant used in the Trident II D-5 Fleet Ballistic Missile. It is because of explosive hazard that the higher energy military solid propellants are not used in commercial launch vehicles except when the LV is an adapted ballistic missile already containing HMX propellant (example: Minotaur IV and V based on retired Peacekeeper ICBMs). The Naval Air Weapons Station at China Lake, CA developed a new compound, C6H6N6(NO2)6, called simply CL-20 (China Lake compound #20). Compared to HMX, CL-20 has 14% more energy per mass, 20% more energy per volume, and a higher oxygen-to-fuel ratio. One of the motivations for development of these very high energy density military solid propellants is to achieve mid-course exo-atmospheric ABM capability from missiles small enough to fit in existing ship-based below-deck vertical launch tubes and air-mobile truck-mounted launch tubes. CL-20 propellant compliant with Congress' 2004 insensitive munitions (IM) law has been demonstrated and may, as its cost comes down, be suitable for use in commercial launch vehicles, with a very significant increase in performance compared with the currently favored APCP solid propellants.
Just google "high energy composite propellant". That's what my stuff is all filed under. There was some fancy ATGM that has RDX in the motor, too. Javelin maybe.
So. We now have an idea of how we get our missile to detonate near its target, what kind of warhead it should use and how selfsame is constructed, and how to propel it all the way up there.
But how the fuck do you:
>A: Know where the targets even ARE?
>B: Steer the missile up there TO it?
This is the most technically complex part of the whole shebang, and the part that I've spent the most time researching. I'm not an electronics guy by nature, and most of this stuff started at a level well over my head.
We're going to start with the basic concepts.
>How do you spot a target aircraft?
This is a problem almost as old as flying itself, and one that has gotten much harder as aircraft technology has advanced. As airspeeds get faster and flight ceilings get higher, detection technology has to keep up. Else by the time you've spotted him and reacted, he's already bombed/droned you and flown off in some other merry direction.
Message too long. Click here to view the full text.
Bump. This thread isn't done yet, just been preoccupied.
I need more of these for bed time readings.
>Hot springs on Saturn's icy moon Enceladus suggest that the floor of the satellite's subsurface ocean may be home to near-boiling temperatures, researchers say.
>This finding is the first evidence of active hydrothermal vents beyond the oceans of Earth. Moreover, conditions deep under the icy surface of Enceladus could be similar to those that gave rise to the first life on Earth, the researchers reported in the new study.
>The sixth largest of Saturn's moons, Enceladus has a diameter of only about 314 miles (505 kilometers). This makes it small enough to fit inside the borders of Arizona.
Pretty fucking neato.
Hmm, haven't heard anything about that.
lol in 2312 ( a really good book) they find microbial life on Enceladus and hippies promptly ingest it. Lulz ensue.
>Aluminum oxynitride is a polycrystalline transparent ceramic that's transparent, light, and very strong, as is illustrated in the video of ALON in action above. The Massachusetts-Based company Surmet was awarded a $4.66 million contract by DARPA to develop a cost-effective way to manufacture this clear aluminum, which at this point is still impractical as compared to, say, sapphire.
That's the ticket, laddie.
>lets use rubies and sapphires to protect us and our cellphone screens
This is hilarious, I want to see diamond windows soon
you do realize that synthetic sapphire is routinely used on high-end watches?
>A bioengineer and geneticist at Harvard’s Wyss Institute have successfully stored 5.5 petabits of data — around 700 terabytes — in a single gram of DNA, smashing the previous DNA data density record by a thousand times.
add more different nucelobases and the amount of data stored increases exponentially.
It increases as log_2(#bases). How did you come up with exponential?
Because people use "exponentially" for some reason in a myriad ways that don't work, when they're actually looking at geometric, logistic or hyperbolic growth functions.
Most of us are bad at math so we dont actually know the difference.
Why not replace them with multitool/autoshotgun/flamethrower robotic hands?
>inb4 you can't hug your children with multitool/autoshotgun/flamethrower robotic hands
I would probably go with a regular hand because it is extremely versatile and most things are made to be used with a regular hand, like cars, doorknobs, and so on.
That said, the hand would be on a universal quick detach mount on the wrist area, to allow simple plopping on and off of specialized hands. I have little interest in heavy, cumbersome, gun-knife-multitool-dildo-cupholder-lamp-camera-waterbottle hands, and instead would rather snap into a mostly dedicated toolhand.
I wonder what guns would look like in this QD arm mount configuration, because regular ergonomic concerns are moot with a gear hardpoint.
And it's actually so fast paced, that we are probably even more advanced than we know. There's a lot of research and development coming out of smaller companies and labs and so many are in this sector and doing work on it that we don't know that the next big development might already be done.
It also happened at the perfect time. Lots of vets with missing limbs, the technology was starting to come online, and lots of funding. Now that serious progress is being made... dunno where the limit is.
My main computer's hard drive died recently, and with it went nearly all my images, videos, and documents.
Stupidly, I never backed it up. I was wondering if you guys had any tools to recommend fro recovering the data.
Sorry to hear that man. I'd recommend DiskDigger as a basic tool for a beginner. I've used is several times in the past and it worked for my purposes.
Does it spin up, but not load Windows? If so, you can probably just slave it in another computer and transfer your files off.
If you plug it in and find that it has dropped its partition, there are software tools that can help. Or if it just makes clicking noises, or doesn't spin, you're probably looking at more in depth physical troubleshooting that requires the replacement of parts (i.e. a professional recovery service, unless you happen to have the parts/equipment).
But chances are pretty good that you can get your stuff back just by plugging the hard drive into another computer.
It won't load windows, when I try to start it in safe mode it freezes part way through. When I tried to plug it into my laptop with one of those cords, it can see that the disk is attached but views it as a CD-Rom drive with nothing in it.
I don't think it works like that but if the desktop is still powering on just not running Windows, you can save your data by running off a Ubuntu live disc
Download the ISO with your laptop and burn it to a disc or follow the instruction to make a bootable USB drive then boot off it. Select "Try Ubuntu" then it will give you a working OS and you can see the data on the HDD and do what you need to do with it.
There is a good change it might have virus/spyware or worse case HDD is going bad
>The reason why limpets’ teeth are so strong is the structure of a hard mineral-protein composite called goethite.
>“The whole tooth is slightly less than a millimetre long but is curved, so the strength is dependent on both the shape of the tooth and the material,” Barber said. He suggested the durable material—its fibres “just the right size” to make a super resilient structure— could be replicated to make cars, boats, and airplanes.
The only important thing we should be asking ourselves is if enough snails could chew through a tank.