Dak

can we really be sure that the world will still exist tommorow? no. there is a chance (albeit an extremely slim one) that a meteor will strike the earth, or that the sun will explode and burn the earth to ash. reguardless of how unlikely these events are, the possibility still exists so we cannot be absolutely 100% certain that the earth will still exist tomorrow, ie

certanty that earth will still exist tommorrow < 1

your binary model of certanty only allows us to have a certanty level of 1 or 0. so what do we say about our certanty that the world will exist tommorow? do we round it up to 1, and ignoor the slim but very real chance that the earth will get hit by a meteor before tomorrow? or, with 1 and 0 as the only options, and with us not being certian to a level of 1, do we simply say that our certanty level is 0?

your binary model also yields a paradox: if we are not 100% certain that the world will still exist tomorrow, and we are not 100% certain that the world will not exist tommorow, then what is our certanty that the world will still exist tomorrow?

not 1, as we are not 100% certain that the world will still exist tommorrow.

not 0, as this is equivelent to saying that we are 100% certan that the world will not exist tomorrow (which is not true).

and not a certanty of 0<x<1, as your model does not allow this.

so, when asked "will the world still exist tomorrow", the only answre that i see your model allowing is "i cannot comment".

or "we cannot be certain", but in this case atleast, we can be pritty certain that the world will, in actual fact, exist tomorrow.

and we can quantify our level of (un)certanty by saying that we are "almost 100% certain". which is incompatible with your model.

just rationaly thinking about 'how certain you are that the world will still exist tommorow' compared to 'how certain are you that a tossed coin will land heads'. neither of them has a certainty of either 1 or 0, yet you are clearly certain of the validity of both statements to different levels . ie, almost 100% certain of the validity of the statement 'world will still exist tomorrow', only roughly 50% certain of the validity of the statement 'a tossed coin will land heads'. there for you can quantify uncertanty in terms other than 1 and 0.

unless were talking sematics here, ie that the word 'certain' is an absolute?

hmm, interesting. but i guess if the Fe oxidises, then the structural integrity of the alloy will be disrupted, bits of the other metals will fall away from the alloy and float away from the stainless steel, allowing it to oxidise away from the Fe.

or if oxygen is being produced in abundance at one of the eletrodes, aslong as the ratio of O:Fe is greater than 1.5 O2 : 1Fe, then the Fe would be oxidised to Fe2O3 and there would still be sum O2 left over for the other metals.

(umm, just read that last bit and dont know whether it makes sense. its been a long time since i did non-bio-chemistry)

actualy, thinking about it how dus the stainless steal rust in the first place? i thought the whole point of stainless steel is that the chrom layer prevents oxidisation?

Lol, this reminds me of the aqua detoxifyer machine. it was a foot spa that was loaded with brine, and an eletrical current passed through the water and your feet, allegedly driving all the nasty toxins out of your body through the pores in your feet. As 'evidence' for the detoxifying effects of the miraculouse aqua detoxyfier, patients attention was drawn to the layer of brown scum of 'toxins' that magically formed at the top of the water.

in your case, just as in the aqua detoxifyer, the brown scum is ferrouse oxide ie rust, caused by the H2O, NaCl and eletricity rapidly oxidising the ferrouse eletrodes.

see here for more info.

(the funny thing is, as the conductivity of salt-water is significantly greater than the conductivity of your feet, very little (if any) electrisity is actually passed through the feet)

as for the green stuff. umm...

well stainless steel has more metals than Fe in it, chromium, nickel and myobium mainly, so maybe the oxidised forms of one of these metals is green.

what containter is the water kept in? if it is made with copper, then i suppose the green stuff could be copper oxide.

it leaves a brownesh greenish residue on my finger when I touch it.

as a biochemist i feel obliged to advise you not to poke unknown substances with your finger. also, you might want to do the experiment outside or in a well ventelated place (the extracter fan above some cooking hobs will do) incase chlorine gas is created from the salt -- even small quantities of chlorine are VERY unplesant to inhale. im talking bleeding lungs here.

My question: Would you be surprised if it was black?

Your answer: Yes and no.

alright, badly worded.

yes i would be surprised because i was 99.00990099(recuring)% sure that the next swan would be white

but i wouldnt be absolutely flabbergasted, because a (roughly) 1% chance is still a chance -- and iv seen enough things that have only a 1% chance of happening fail to happen, that its only to be expected that a few events defy the odds and actually hapen dispite the low probability that they would.

which is the whole point of assighnin percentiles to certanty -- its not binary.

ie: no, u cannot be 100% certain of the colour of the last swan, but you can be pretty dam sure

well i dont care what anyone says, i KNOW that the rings of eternal life work

i'v been wearing one for the past month and, in the entire time that i have been wearing them, i HAVE NOT ONCE DIED!

proof. i rest my case. etc.

you forgot exessively long words. i know genuine scientificul articles can be full of long words, but 1/ we usualy only use long words where they are genuinely useful, and 2/they are usualy used correctly.

scientists call a spade a shovel; pseudo-scientists usualy call a spade a manualy-powered turf-displacement utility, with a hyperbolic soil-penetration component diametrically opposite a quasi-ergonomical manual-interface phlange which is, itself, adjacent to the axial support structure -- the three components synergistically affording significantly enhanced botanical inhumation powers.

they think the long words impress people and make the statement sound scientifical

so you have a bag with 100 swans. you pull out 99, and they are all white.

two hypothesis can fit the fact that 99 swans are known to be white, vis:

H1: 99 swans are white and 1 swan is non-white

H2: 100 swans are white.

the probability that the first 99 swans out of the bag will be white is the P(1st swan is white)*P(2nd swan is white)*P(3rd swan is white)...*P(99th swan is white)

the probability that a white swan will be chosen = the number of white swans/the total number of swans.

if H1 is true, then the P(first 99 swans are all white) = (99/100)*(98/99)*(97/98)...*(1/2), 1/2 being the 99th choice, where according to the hypothesys there would be two swans left, one of which is white and one of which is not. this gives a probability of 1/100 (logical, concidering the probibility that the non-white swan would be picked last is equivelant to the probability that the non-white swan would be picked 1st = 1/100)

so there would be a 1/100 chance of getting the observed results if H1 is the case.

If H2 is the case, then there would be a 100/100 chance of getting the observed results (if all 100 swans are white, the chance of the first 99 swans being picked would be 1).

not entirely sure where to go from here, but i think that the following is logically/mathematicaly true...

probability of obtaining the observed result if the given hypothesis is true:

H1: 1/100

H2: 100/100

therefore, H2 is 100 times more lightly to yield the observed results than H1, ie P(H1 is corect) = 1/101, P(H2 is correct) = 100/101

or in other words, H2 has a 99.00990099(reccuring)% chance of being correct,

accept H2 (at 99% confidence interval)

so not certain that the last swan would be white, but would quite highly expect it to be. have also quantified my uncertanty with the confidence interval, which is essentialy the P(my assumption is correct)

would i be surprised if it were black? yes and no. yes because there is only a 1/101 chance that it would be non-white. no because 1/101 chance is not the same as 0 chance. im sure that things with only a 1/101 chance of happening fail to happen just over 99% of the time, but occasionaly they do happen

the one that i really like is when they ask me "what? and we just HAPPEN to be on the planet that life sprung up on? out of all the billions of planets in the universe it just magically takes place on OUR planet? what are the odds of that?"

 

/chuckle

lol; what i always say in reply to this is:

immagine that you are a timless entity. you watch a planet coalesc out of space-dust and achieve a stable orbit around the nearest sun, you see its climate stabalise, mountian ranges rise and fall, oceans form, freze, thaw, you see the tectonic plates move about, and eventually you see the sun expand as it reaches the end of its fuel supply and you see the planet burned back into space-dust: all without life spontaniously occournig.

you now choose another planet, just coalescing out of space-dust, and you watch this one. again, after millions of years, it is distroyed without ever having spawned life.

you find another newly-forming planet...

...you have just watched your 9,999,999,999th planet be distroyed without forming life. you start to watch a new planet, coalescing from space-dust, you see its climate stabalise, mountains rise and fall, continents shift around on the changing oceans, and then, after failing to happen so many times, you finally see life emerge, and gain the capability of inteligent thought and language. then one of them goes "ooh, isnt it unlightly that we just randomly happened? the odds must be one-billion-to-one!"

people generaly still wont understand. i think that people who dont understand the logic just plain and simple dont want to understand the logic, because they percieve it to contradict their religion.

"hmm" indeed... alot of annoying hurdles to sort out in this idea

hiv reverse-transcribes in the cytoplasm before transporting a DNA copy of its genome into the nucleus, so cytoplasmic ResNms could cut it up in the cytoplasm and leave the host genome intact, as long as the ResNms do not gain entry into the nucleus.

i believe that eukaryotes probably ditched the bacterial Res-Mod system as we use methylations for other purposes -- cytosine methylation is used to deactivate genes and adenosine methylation performs an unknown function in eukaryotes, but it is thought to maybe be involved in binding long loops of dna to the nuclear membrane during dna synthesis (any imput on the role of A methylation would be appreciated), and C and A are the only two bases that can be methylased. i guess gene regulation is a more important function than cellular immunity, as we already have an immune system to protect us, and methylations cannot easaly perform both functions simultaniously.

oh right, open reading frame. makes scence now

hi there, cheers all for your replys

the idea that im investigating in my dissertation is the potential use(s) of restriction enzymes to combat hiv infection, so to answre the issues that you rased:

the gene would not be inserted into the gamete, but into the genome of the cd4+ cells (helper-T-cells, macrophages, dendrites) using a HIV vector

the host genome would be protected from restriction by either: using a restriction enzyme that cannot re-enter the nucleus after being trannslated (which could restrict the HIV genes as they travel through the cytoplasm); using a restriction enzyme that is regulated by a HIV-tat promotor, ie upon hiv infection would create a restriction enzyme to completely distroy the cell; or introdusing both the restriction enzyme gene and the methylation enzyme gene aswell,

There should be no reason why the ORF cannot be properly transcribed and translated. I guess It boils down to

1) if the protein produced will be functional (my guess yes).

2) What interaction said REN if functional will have with a eukaryotic cell.

I think this second question is where the problem lies that either the cell will actively degrade the REN or that the REN will degrade your hosts DNA. So you'd either get no RENS, or a cell that dies once properly modified.

if it would be translated, then does anyone know whether or not the cell would degrade the res enzm? i cant find any published info on this anywhere (unsurprisingly).

and what does ORF mean?

cheers again for all your replys

yup, in prokaryotes it protects the cells genome from being cut by the restriction enzymes. in eukaryotes, cytosine methylation plays a role in deactivating genes, but no one seems to be sure of the role of adenosine methylisation in eukaryotes?

hi everyone

am currently wrighting my bacholorate dissertation, and was wondering if i could pick your brains on a subject?

basiccally, i was wondering if anyone knows whether the prokaryotic genes encoding restriction enzymes will be properly expressed by eukaryotes, in particular humans

i cannot find any published data on this subject, so if anyone has any idea -- anecdotal or otherwize -- i would very much appreciate it

thanx all

does anyone know what role adenosine methylation plays in eukaryotes? iv looked through text books, papers, and asked my lecturers at uni, and as far as i can tell it seems that their is some evidence to suggest that adenosine plays some sort of role in dna replication and/or transcription, but no one seems to be sure

would appresiate any thoughts/nuggets of wisdom

thanx in advance