Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 Internet speed test! ×

Comment junk DNA not trash DNA (Score 1) 116

Can junk DNA be seen as "potentially useful junkyard parts" that some random mutation might re-activate into a gene or part of a gene? Is it actually handy to have these around to allow for rapid bigger changes of set of active genes than just a few small mutations in the active genes can do?

That why they are called junk DNA and not trash DNA, because at least part of it is ready to be reused later.

Some parts will be to control which genes are actually activated, some might even only be necessary to determine how the DNA is folded to determine what genes get more exposure, but the thousends of broken and useless copies of genes around in the junk DNA surely also have the function of collecting mutations until they might get by chance to something useful one day.

While even proteins coded by genes many parts are just filler, the important parts do not allow much changes to still get a surviving organism. You do not want too much mutations on the active genome, or you waste too much with sterile mutants. But to get something truly different, you often need to do many changes at once, and the chances to get there with only active genome are practically not there.

Comment Re:I must be stupid (Score 1) 255

Inertial Mass comes from Newton's second law:

F = m_i * a

That is, inertial mass determines how much an object will be accelerated by a particular force.

Gravitational Mass comed from Newton's law of graviation:

F = G * m_g1 * mg2 / r ^2

That is, the magnitude of the gravitational forces between two objects.

The question is whether the two definitions of mass are interchangable (e.g. does m_i = m_g1?). That appears to be the case for normal matter, which we can tell because all objects accelrate at the same rate in a given gravitational field regardless of mass. But it doesn't have to be the case.

That assumes "forces" are the real things. if you rather look at accelerations, then the acceleration you get by being in the gravitational field of another body does only depend on their mass, not at all on your mass. That's why general relativity images the gravitational forces as not directly effecting you, but instead the geometry of space.

So in that light the question of "why is gravitational mass the same as inertial mass" boils down to: why is your gravitational force of exactly that size compared to your intertial mass so that gravitational forces are symmetric? i.e. why does earth's gravitational force on you seem to be exactly the same as the force you are enacting on earth? i.e. why does action == reaction hold even if you do no start with forces as the primary physical objects?

Comment Said to be safe can be more dangerous. (Score 1) 180

While making it harder for terrorists is nice, it might actually increase the rate of accidental fertilizer plant explosions.

See for example http://en.wikipedia.org/wiki/Oppau_explosion for an example what happens if people think their fertilizer cannot explode so the easiest way to get some stuck in a silo out is a little charge of dynamite.

Comment Re:Metal detector? (Score 1) 172

"That would be highly ineffective, since chocolate bars are wrapped in tin foil."
Is it really the 1910's in the UK?

I have not seen a tinfoil wrapped candy bar for over 30 years. plastic wrapped with a Metallica plastic? yes!

I don't know about UK, but here in continental Europe, the good chocolare usually has tin foil, while the cheap chocolate and the chocolate-containing-stuff (you are not allowed to call it chocolate if you do not use chocolate butter but some replacement) use some cheap replacement (often not even metallic to make it clear it is a really super-cheap one).

Comment graphene vs post-silicon (Score 5, Insightful) 99

Just because graphene might became useable does not mean it will replace silicon.

Silicon has quite some head start, so might survive the alternatives quite some time even in those use cases where alternatives are bette (just like it happened with spinning hard discs as storage medium, or explosion engines for cars).

And likely it has quite some downsizes that make it unfit for many purposes where silicon shines. Have they for example solved the problem of graphene to always need some current? Being able to build ultra-fast chips is nice, but if there is no way to reduce power usage of parts currently usused that might make it unfit for all but nieche markets. (Well, high-performance needing nieche markets and gamer's PC most likely).

Comment Re:leave the EU (Score 3, Interesting) 130

1. Session cookies are key in allowing Google to track and store more data than it should.

Err, no, that would be persistent cookies. Session cookies are deleted whenever the browser session ends, so it makes tracking rather pointless. The cookies Google (and every other company) uses to track are set to expire years in the future.

So you always open your browser for only one site and close it afterwards? And never look at two sites at the same time?

If you like it or not, the problem with cookies is something that can only be solved by law.
There are some sites only working with cookies (mostly for stupid reasons), so you cannot disable cookies globally.
Almost any site with advertising gives you a tracking cookie, per advertisement, so no browser will ask people to accept cookies by default as people will be utterly confused. And because any browser accepts them by default, sites can just add tracking cookies without many people complaining. So no browser can switch to "ask-before-request" as too many sites use them....

So you either have to accept that any site will track what other sites you visit and give the advertisers your profile
(and once one of thoe sites also has your login, connect that profile to your identify), or you have to use regulation.
One might differ whether people have a right on privacy or websites have a right to get revenues. But if one considers a right for privacy, regulation is the only solution in this case.

Comment MRSA (Score 2) 133

MRSA is no the product of a total war on bacteria, but the product of a careless war.

Our use of antibiotics is like sending a single policeman with a single gun to every incident reporting and not caring if they return. In most cases it will be enough, but in the long run there will be many criminals with police guns in their hands
(and even if they do not need the new guns, they still get fresh ammo all the time).

Hospitals are then favelas handled like that, i.e. sending one or two policemen with automatic guns into areas where everyone already has guns, perhaps sending them in until they return and bring back all the weapons in one house, but not counting all the weapons you lost, not looking if anyone leaves the house with some of your weapons and hides somewhere else, not caring for people walking around with your weapons in the streets and so on.

The big weapons against MRSA are basic hygiene and checking your employes. Just regularily testing your employees and getting rid of any MRSA they carry around helps a lot. Teaching people to wash your hands between touching patients instead of between touching sterile items is also said to help a lot.

Comment Re:Hm (Score 5, Insightful) 105

People might be sceptical how big the problem is, but the analysis itself and the diagnosis is sound. Most people are only suprised they did not think about it before.

The math is simple: If you have a buffer that is never empty, every package will have to wait in the buffer. If you have a buffer full all the time, it serves no purpose but only defers every packet. And given that RAM got so cheap that buffers in devices grew so much more than bandwidth, you now often have buffers big enough to hold packets needing full seconds to send them all. Such a buffer running in always-full mode means high latency for no gain.

All additional factors of TCP going harvoc when latency is too high and no longer being able to compute how fast to optimally send if no packages get dropped only make the situation worse, but the basic is simple: A buffer always full is a buffer only having downsizes. The more the bigger it is....

Slashdot Top Deals

Like punning, programming is a play on words.