The efficacy of a medical test is determined by three numbers. 1) The real incidence rate - what percent of the population (after the fact) actually has the condition. 2) The false positive rate. 3) The false negative rate.
The problem with the PSA test is that while the real incidence rate is relatively high, the false positive and false negative rates are extremely high.
1) The incidence rate varies with age and ethnicity. According to the CDC (and wikipedia, for what it's worth), (http://www.cdc.gov/cancer/prostate/statistics/race.htm), the age-averaged rate is 100 per 100,000 for asians, 160 per 100,000 for white and 250 per 100,000 for black men. But they don't recommend the test for men under 45. And age really is the determining factor. (http://seer.cancer.gov/publications/prostate/inc_mort.pdf). So, let's assume an incidence rate of 10% for 55 year old men for purposes of this exercise. - for 75 year old men, it's probably closer to 90%, for 20 year old men, essentially zero.
2) According to the National Cancer Institute (http://www.cancer.gov/cancertopics/factsheet/detection/PSA), the false positive rate is 65-75%. Giving the test the best chance, I'll take the lower limit of 65%.
3) I haven't found a definitive source for the false negative rate, but wikipedia cites a paper giving a 25% false negative rate. Let's give it the benefit of the doubt and call it 20%.
Source... ^ Thompson IM, Pauler DK, Goodman PJ, Tangen CM, Lucia MS, Parnes HL, Minasian LM, Ford LG, Lippman SM, Crawford ED, Crowley JJ, Coltman CA (May 2004). "Prevalence of prostate cancer among men with a prostate-specific antigen level or 4.0 ng per milliliter". N. Engl. J. Med. 350 (22): 2239–46)
So - give a population of 1 million men a PSA test and here's what you get.
100,000 men have prostate cancer 900,000 do not have prostate cancer.
Of the 100,000 men who DO have prostate cancer... a) 20,000 test negative (a problem, but what are you going to do? This was my father's case (see below)) b) 80,000 test positive (okay, but do you need treatment? Odds are you'll die of something else first (see below))
Of the 900,000 who do NOT have prostate cancer. c) 585,000 test positive (the real problem) d) 315000 test negative. (good on yer.)
The real problem is that honking huge false positive rate. If you test positive, there's still less than a 50% chance that you actually have prostate cancer, and even if you do, it's probably not going to make a damn bit of difference over the course of your life, but it's still very very scary and you get a biopsy or have radiation treatment and risk impotence and/or incontinence and possibly seriously reduce your quantity of life for the rest of your life for no good reason. It's even more complicated by the fact that the PSA level goes up naturally as you age. If your level goes from 4 to 10 over 10 years, what does it mean? Flip a coin.
That said, given that my father, both his brothers and my paternal grandfather all died from prostate cancer (between the ages of 90 and 94, I'll grant you - that's the thing. The vast majority of men will die of something else before the prostate cancer kills them), my doctor recommends continuing to take the test every 5 years.
Which describes almost every "red" state in the Union.
Citation needed. Badly.
Okay, here's a link to a special report by the Tax Foundation (a very conservative anti-tax organization, btw). Line up the states by the ratio of federal spending to taxes paid. The highest ratios? New Mexico, Alaska, Mississippi, Alabama, the Dakotas, Virginia, West Virginia, Montana, Idaho. The lowest ratios? New York, California, Minnesota, Illinois, New Jersey, Connecticut, Mass. The correlation isn't perfect (e.g. Texas is receives slightly less in federal expenditures than it pays in taxes, and obviously, it's pretty durned red. Iowa is the reverse), but it's pretty strong.
A little googling will reveal a number of additional citations.
250 club here. It's the greatest. We used to do this every winter at a lake up on the Minnesota/Manitoba border. The sauna was right on the lake shore with a ramp running down to the water. Use a chain saw to cut a hole in the ice at the foot of the ramp. Sit in a 120 degree F sauna for a good long while. Run down the ramp and jump into the water. Get out in a -30 degree F ambient temperature. Crazy thing is that you can stand around outside for quite a while and be perfectly comfortable - with huge clouds of steam billowing off you as the water evaporates. Note - wear socks when you run down the ramp - the ice crystal are sharp.
The horrible irony is that torture really doesn't work all that well. The information extracted via torture is notoriously unreliable. The victim ends up telling the torturer what he/she thinks the torturer wants to hear, rather than the truth - often exagerating, falsely implicating others, etc.
I was using OO as an Office replacement for a while. As a word processor, I actually prefer OO, but as a spreadsheet, there was only one crucial function that caused me to switch back, namely, Data>Text to Columns.
I can work around it using sed scripts to parse the file before opening it in OO, but the extra step is enough of a hassle to interfere with my workflow. I also don't think it's likely that the casual user is going to want to deal with sed and regexp's. I also realize that if I really wanted the feature, I should buckle down and implement it myself, but frankly I don't have the time or the skill.
TC
Indeed, the preponderance of the evidence seems to be that ethanol can be produced from perennial crops with a positive BTU balance, but land use is the real problem. At the risk of being US-centric, according to the US Dept. of Energy, total 2004 gasoline consumption was approximately 65,700,000,000 gallons (sorry, can't find the link - this is from an analysis I did last year. If someone has a link to more current figures, or figures that differ, I'd appreciate seeing them.) Assuming very optimistically that one acre of farmland can produce enough biomass for 1000 gallons of ethanol, then 65 million acres would be required to replace gasoline with ethanol - about twice the area of the state of Georgia.
Obviously, completely replacing gasoline with ethanol is not a realistic goal, but the US is currently undergoing a rapid loss of arable land, so it is unlikely that even 6.5 million acres can be freed up to produce the ethanol required to replace 10% of gasoline consumption. The danger is that ethanol production will intrude on (1) less productive land - thus decreasing the efficiency of ethanol production and (2) more sensitive eco-systems, especially in the developing world. On the other hand, as other posters have pointed out, ethanol has some advantages in terms of emmisions, and politically it is advantageous to reduce dependence on fossil fuels, so replacing subsidized, economically non-viable crop production with ethanol production and using otherwise wasted bio-mass for ethanol production makes sense.
Slashdot Mirror
The efficacy of a medical test is determined by three numbers.
1) The real incidence rate - what percent of the population (after the fact) actually has the condition.
2) The false positive rate.
3) The false negative rate.
The problem with the PSA test is that while the real incidence rate is relatively high, the false positive and false negative rates are extremely high.
1) The incidence rate varies with age and ethnicity. According to the CDC (and wikipedia, for what it's worth), (http://www.cdc.gov/cancer/prostate/statistics/race.htm), the age-averaged rate is 100 per 100,000 for asians, 160 per 100,000 for white and 250 per 100,000 for black men. But they don't recommend the test for men under 45. And age really is the determining factor. (http://seer.cancer.gov/publications/prostate/inc_mort.pdf). So, let's assume an incidence rate of 10% for 55 year old men for purposes of this exercise. - for 75 year old men, it's probably closer to 90%, for 20 year old men, essentially zero.
2) According to the National Cancer Institute (http://www.cancer.gov/cancertopics/factsheet/detection/PSA), the false positive rate is 65-75%. Giving the test the best chance, I'll take the lower limit of 65%.
3) I haven't found a definitive source for the false negative rate, but wikipedia cites a paper giving a 25% false negative rate. Let's give it the benefit of the doubt and call it 20%.
Source...
^ Thompson IM, Pauler DK, Goodman PJ, Tangen CM, Lucia MS, Parnes HL, Minasian LM, Ford LG, Lippman SM, Crawford ED, Crowley JJ, Coltman CA (May 2004). "Prevalence of prostate cancer among men with a prostate-specific antigen level or 4.0 ng per milliliter". N. Engl. J. Med. 350 (22): 2239–46)
So - give a population of 1 million men a PSA test and here's what you get.
100,000 men have prostate cancer
900,000 do not have prostate cancer.
Of the 100,000 men who DO have prostate cancer...
a) 20,000 test negative (a problem, but what are you going to do? This was my father's case (see below))
b) 80,000 test positive (okay, but do you need treatment? Odds are you'll die of something else first (see below))
Of the 900,000 who do NOT have prostate cancer.
c) 585,000 test positive (the real problem)
d) 315000 test negative. (good on yer.)
The real problem is that honking huge false positive rate. If you test positive, there's still less than a 50% chance that you actually have prostate cancer, and even if you do, it's probably not going to make a damn bit of difference over the course of your life, but it's still very very scary and you get a biopsy or have radiation treatment and risk impotence and/or incontinence and possibly seriously reduce your quantity of life for the rest of your life for no good reason. It's even more complicated by the fact that the PSA level goes up naturally as you age. If your level goes from 4 to 10 over 10 years, what does it mean? Flip a coin.
That said, given that my father, both his brothers and my paternal grandfather all died from prostate cancer (between the ages of 90 and 94, I'll grant you - that's the thing. The vast majority of men will die of something else before the prostate cancer kills them), my doctor recommends continuing to take the test every 5 years.
Can't you see its offending 1.6 billion people, yet you go ahead and do it.
Precise numbers are hard to come by, but, for example, adherants.com gives..
2.1 billion Christians
1.6 billion Muslims
1.1 Secular/Nonreligious/Agnostic/Atheist
Can't you see it's offending 1.1 billion people, yet you go ahead and do it.
Citation needed. Badly.
Okay, here's a link to a special report by the Tax Foundation (a very conservative anti-tax organization, btw). Line up the states by the ratio of federal spending to taxes paid. The highest ratios? New Mexico, Alaska, Mississippi, Alabama, the Dakotas, Virginia, West Virginia, Montana, Idaho. The lowest ratios? New York, California, Minnesota, Illinois, New Jersey, Connecticut, Mass. The correlation isn't perfect (e.g. Texas is receives slightly less in federal expenditures than it pays in taxes, and obviously, it's pretty durned red. Iowa is the reverse), but it's pretty strong. A little googling will reveal a number of additional citations.
and I have in it a To-Do list, which essentially is a wish-list No it's not.
It's a wish-I-didn't-have-to-do list.
Here are a couple of talks/demos by Hans Rosling - who I think (but I could be wrong) was the developer of gapminder. Very interesting analyses of poverty and development based on the UN databases. http://www.ted.com/index.php/talks/view/id/92 http://www.ted.com/index.php/talks/view/id/140
250 club here. It's the greatest. We used to do this every winter at a lake up on the Minnesota/Manitoba border. The sauna was right on the lake shore with a ramp running down to the water. Use a chain saw to cut a hole in the ice at the foot of the ramp. Sit in a 120 degree F sauna for a good long while. Run down the ramp and jump into the water. Get out in a -30 degree F ambient temperature. Crazy thing is that you can stand around outside for quite a while and be perfectly comfortable - with huge clouds of steam billowing off you as the water evaporates. Note - wear socks when you run down the ramp - the ice crystal are sharp.
Point well taken. obDictionNazi
obGrammerNazi: http://web.mit.edu/writing/temp2/flaunt.htm
The horrible irony is that torture really doesn't work all that well. The information extracted via torture is notoriously unreliable. The victim ends up telling the torturer what he/she thinks the torturer wants to hear, rather than the truth - often exagerating, falsely implicating others, etc.
I was using OO as an Office replacement for a while. As a word processor, I actually prefer OO, but as a spreadsheet, there was only one crucial function that caused me to switch back, namely, Data>Text to Columns. I can work around it using sed scripts to parse the file before opening it in OO, but the extra step is enough of a hassle to interfere with my workflow. I also don't think it's likely that the casual user is going to want to deal with sed and regexp's. I also realize that if I really wanted the feature, I should buckle down and implement it myself, but frankly I don't have the time or the skill. TC
Indeed, the preponderance of the evidence seems to be that ethanol can be produced from perennial crops with a positive BTU balance, but land use is the real problem. At the risk of being US-centric, according to the US Dept. of Energy, total 2004 gasoline consumption was approximately 65,700,000,000 gallons (sorry, can't find the link - this is from an analysis I did last year. If someone has a link to more current figures, or figures that differ, I'd appreciate seeing them.) Assuming very optimistically that one acre of farmland can produce enough biomass for 1000 gallons of ethanol, then 65 million acres would be required to replace gasoline with ethanol - about twice the area of the state of Georgia. Obviously, completely replacing gasoline with ethanol is not a realistic goal, but the US is currently undergoing a rapid loss of arable land, so it is unlikely that even 6.5 million acres can be freed up to produce the ethanol required to replace 10% of gasoline consumption. The danger is that ethanol production will intrude on (1) less productive land - thus decreasing the efficiency of ethanol production and (2) more sensitive eco-systems, especially in the developing world. On the other hand, as other posters have pointed out, ethanol has some advantages in terms of emmisions, and politically it is advantageous to reduce dependence on fossil fuels, so replacing subsidized, economically non-viable crop production with ethanol production and using otherwise wasted bio-mass for ethanol production makes sense.