Film vs digital detector doses are comparable, but when you factor in repeats due to improper exposures, film is a little higher. It's not enough to make it worth switching to digital detectors based on dose considerations alone though. There are plenty more compelling reasons to switch from film to digital.
The wider dynamic range of digital detectors gives a lot of flexibility when it comes to the amount of exposure used. If not enough radiation is used, a digital detector will produce a noisier, but often still useful image. The film image on the other hand will be too light and generally non-diagnostic. If too much radiation is used, the digital detector will produce a pretty, low noise image where the film image will end up being too dark and often non-diagnostic.
It is ultimately the responsibility of the imaging professionals (radiologists, technologists and medical physicists) to develop proper imaging protocols to suit the age and sizes of the patients being imaged, not only from a radiation dosimetry point of view, but also an image quality point of view.
For a long time now the tendency, particularly with CT imaging, has been to use a one size fits all protocol for everybody.
The move to reducing medical radiation exposure has been going on for several years now. Recent high profile incidents (such as what happened with CT patients getting CT angiograms at Cedars Sinai) prompted many institutions to review their imaging protocols. The Image Gently campaign has worked towards getting institutions to develop pediatric specific imaging protocols for several years now. For procedures involving potentially high radiation exposures, radiologists review and protocol the requests to make sure the requested exam fits the clinical indications. Outpatient imaging centers performing CT imaging need to get their scanners accredited in order to get Medicare reimbursement. Accreditation by the ACR (American College of Radiology) places dose limits on several types of scans. If a site's protocol results in a radiation dose that exceeds the limits, they fail accreditation and need to adjust their protocols.
The FDA can and should require manufacturers provide the tools to enable imaging facilities to monitor and record the amount of radiation given during a procedure, but it needs to be the responsibility of the users to make sure the imaging equipment is used properly on patients.
for a photography newbie, i'm of the opinion that the specific camera doesn't really matter. They're all more or less the same anyway. what's most important is finding one that you'll want to carry around with you and use. the more you use it the less newb you'll become over time. you'll learn things and by the time you're ready to upgrade you'll know what to look for.
and rather enjoyed it. The ending was different from what I expected or thought it might be, but given the nature of apes, a much more fitting ending than the one I imagined.
the only people the apes kill are the ones that deserved it. on the other side, lots of apes were killed by people.
This has been known for decades. The more time at altitude the LESS you should be exposed to other forms of radiation. That's why they ask you questions about flying before any medical procedure involving radiation. I'll bet the pilots are incredibly pissed about all these scans because for one thing it can reduce their legal flight time.
In the US, medical exposures are not counted against occupational exposure.
To make things worse these things are not just your normal transmission x-ray where you just want to see what photons make it to the sensor and the dark spots tell you where the dense stuff is. What these scanners are doing is providing far more radiation with the aim of getting atoms to absorb and re-emit photons - effectively making you radioactive while the scanner is on. The idea behind that is the wavelengths of the re-emitted photons can be used to determine what elements are present, find metal and perhaps find explosives. Because that really adds up to a shitload of radiation if it's going to scan all the way through you the dose is cut back and you just end up with the skin being exposed to quite a lot and no ability to sense internally hidden explosives.
No. The x-rays being detected are those that scatter off the person being scanned. They are *not* making anybody radioactive in any way. There is no way scattered x-rays are going to tell you the elemental composition of anything. Density, but not composition.
It is also not a "shitload of radiation". If these machines were detecting transmitted radiation instead, that would actually require *more* radiation exposure and would operate more like x-ray units found in hospitals.
"The researchers only tested their methods on so-called feature phones, not smartphones such as Android devices or iPhones. The reason, they said, is that feature phones still are far more prevalent in most of the world than smartphones are, so the target area is much larger."
I tend to hang onto all of my stuff until it breaks beyond repair or is no longer functional for me. I hung on to my Dell Dimension 8100 and kept it going with upgrades and replacements for almost 10 years. It's still usable, but I needed more computing power for number crunching so I got a new computer.
I used my Tungsten T3 for 4 years until it accidentally got washed in the laundry. Replaced it with another one and still using it 3 years later.
I was switching between classes when I heard a friend of mine say the shuttle just blew up. I thought he was just bull-shitting and went on with my day. Then I got home from school and saw all the news coverage. It was a sad day after that.
I've used GeneWeb and really liked it. Written in OCaml, but appears to be dormant. Nothing much has happened with it for a few years now. Still a pretty good program though.
I don't see a trial version of this on the Bundle site....?
I'd likely pay more money if I knew I liked the games and would play them...but if I was buying sight unseen..I'd be a bit hesitant to put out more than $10 or so...
All the games have demo versions available if you visit the website for the game itself (they're linked to from the Humble Bundle site)
Does anybody not see irony in this? Amazon originally started off as an online retailer/clearinghouse helping people purchase hard to find books through affiliated second hand book sellers.
Playing devil's advocate, is it really so bad though? initial "bottom feeder" reaction aside, the thrift store/used book seller makes a sale and presumably makes a little profit, scanner guy posts a listing, makes a sale and some profit, book buyer gets a book they're after. Scanner guy just becomes a middle man, the same way Amazon started off.
That said, I'll stick with my initial bottom feeder reaction and agree with what backwardmechanic said.
Stewart's Calculus (1st ed) still remains on my bookshelf 20+ years after I took my 2 years of undergrad calculus. Even back then it was an expensive text, but was the only one I needed to purchase for 4 calculus courses. It also served me well through the rest of my undergrad and Master's degree. It was one of a handful of textbooks I kept following my Great Textbook Purge of 2007 and I still use it on a regular basis. I've definitely gotten my money's worth out of it.
This is all moot because the world will end in 2012 anyway
it's on the internet, so it must be true.
but if it happens that nothing happens in 2012, i'm sure someone will say there was a slight error in the calculations and say the asteroid will cause the end of the world. after all, what's a couple hundred years on a time scale of thousands of years?
Pay a visit to the library of a nearby university with a CS department (sometimes the departments have their own libraries) and look at the computer science related journals they have (a list of ACM associated journals can be found at http://www.acm.org/publications/panel/journals). Most of what I know about writing papers comes from reading them. The first thing you'll want to do is a literature search on related algorithms, and dig up some of those papers. Read through a bunch of them to see how they're organized, the types of subject material covered (to help you decide which journal to submit to) and the Information for Authors section. The Info for Authors section will tell you everything you need to know about formatting and submitting to that particular journal.
One of the staff librarians can probably help you find material to help you learn about the mechanics of paper writing.
The process from submission to publication (assuming your paper is accepted) will likely take several months to a year and involve one or more revisions.
I bought an HP LJ1012 over 5 years ago for $125. It's an inexpensive low-medium workload printer that works just fine for the small amount of printing I do. I go through a toner cartridge (~$70) every 1-2 years. As others have mentioned, it's pretty easy to find a laser printer for less than $100 these days.
Proton beam therapy is a logical extension of what's already being used. Electron beam therapy is already fairly common and the evolution to protons, with much higher LET (linear energy transfer) and Bragg peak, is just the next step. IANATP (I Am Not a Therapy Physicist) but I wouldn't think the side effects are much worse than conventional (x-ray or electron) therapy treatments and possibly a little less.
For the past few years, Philips has been lagging behind the technology curve when it comes to CT scanners. They're hardly the first to come out with a 256 slice scanner. FTA, the only new thing I see that Philips has brought is the faster rotation time (4 rotations/sec compared to 3 rotations/sec current scanners are capable of).
Actually, OCR is a considerably easier problem than creating a reliable CAD (Computer Aided Diagnosis) system.
There's a lot of research going on in CAD. However, creating a reliable CAD system is far from trivial, and the ones that are currently in clinical use are very task specific and are never used as the primary diagnostic tool. CAD systems are normally used to highlight areas for the radiologist to examine a little more closely. AFAIK, in the US the only CAD systems approved by the FDA are in mammography and do a reasonably good job at finding calcifications, but suck at finding masses. Lots of work going on in CAD for lung masses, but still research.
The type of CAD system you're envisioning is still a long, long way off.
Low field 0.5T magnets found in many stand-alone imaging centers and ortho clinics might be in the $500k-$1M range, but the more typical 1.5T magnet found in hospitals is usually considerably more expensive, with 3T magnets around the $3-4M range.
Slashdot Mirror
bad link to the iFixit blog link
here's the correct one
http://ifixit.org/blog/7401/if...
ahh, there it is now. wasn't there when i first looked at the story
what, no link to the press release?
Film vs digital detector doses are comparable, but when you factor in repeats due to improper exposures, film is a little higher. It's not enough to make it worth switching to digital detectors based on dose considerations alone though. There are plenty more compelling reasons to switch from film to digital.
The wider dynamic range of digital detectors gives a lot of flexibility when it comes to the amount of exposure used. If not enough radiation is used, a digital detector will produce a noisier, but often still useful image. The film image on the other hand will be too light and generally non-diagnostic. If too much radiation is used, the digital detector will produce a pretty, low noise image where the film image will end up being too dark and often non-diagnostic.
It is ultimately the responsibility of the imaging professionals (radiologists, technologists and medical physicists) to develop proper imaging protocols to suit the age and sizes of the patients being imaged, not only from a radiation dosimetry point of view, but also an image quality point of view.
For a long time now the tendency, particularly with CT imaging, has been to use a one size fits all protocol for everybody.
The move to reducing medical radiation exposure has been going on for several years now. Recent high profile incidents (such as what happened with CT patients getting CT angiograms at Cedars Sinai) prompted many institutions to review their imaging protocols. The Image Gently campaign has worked towards getting institutions to develop pediatric specific imaging protocols for several years now. For procedures involving potentially high radiation exposures, radiologists review and protocol the requests to make sure the requested exam fits the clinical indications. Outpatient imaging centers performing CT imaging need to get their scanners accredited in order to get Medicare reimbursement. Accreditation by the ACR (American College of Radiology) places dose limits on several types of scans. If a site's protocol results in a radiation dose that exceeds the limits, they fail accreditation and need to adjust their protocols.
The FDA can and should require manufacturers provide the tools to enable imaging facilities to monitor and record the amount of radiation given during a procedure, but it needs to be the responsibility of the users to make sure the imaging equipment is used properly on patients.
is the one that you carry with you.
for a photography newbie, i'm of the opinion that the specific camera doesn't really matter. They're all more or less the same anyway. what's most important is finding one that you'll want to carry around with you and use. the more you use it the less newb you'll become over time. you'll learn things and by the time you're ready to upgrade you'll know what to look for.
Thanks for all the work you put into /.
it's been my main source of news and laughs for most of the 14 years it's been around.
Best of luck with whatever comes next
and rather enjoyed it. The ending was different from what I expected or thought it might be, but given the nature of apes, a much more fitting ending than the one I imagined.
the only people the apes kill are the ones that deserved it. on the other side, lots of apes were killed by people.
the apes don't really need to get rid of people to take over the planet. humans take care of the problem all on their own
This has been known for decades. The more time at altitude the LESS you should be exposed to other forms of radiation. That's why they ask you questions about flying before any medical procedure involving radiation.
I'll bet the pilots are incredibly pissed about all these scans because for one thing it can reduce their legal flight time.
In the US, medical exposures are not counted against occupational exposure.
To make things worse these things are not just your normal transmission x-ray where you just want to see what photons make it to the sensor and the dark spots tell you where the dense stuff is. What these scanners are doing is providing far more radiation with the aim of getting atoms to absorb and re-emit photons - effectively making you radioactive while the scanner is on. The idea behind that is the wavelengths of the re-emitted photons can be used to determine what elements are present, find metal and perhaps find explosives. Because that really adds up to a shitload of radiation if it's going to scan all the way through you the dose is cut back and you just end up with the skin being exposed to quite a lot and no ability to sense internally hidden explosives.
No. The x-rays being detected are those that scatter off the person being scanned. They are *not* making anybody radioactive in any way. There is no way scattered x-rays are going to tell you the elemental composition of anything. Density, but not composition.
It is also not a "shitload of radiation". If these machines were detecting transmitted radiation instead, that would actually require *more* radiation exposure and would operate more like x-ray units found in hospitals.
FTA
"The researchers only tested their methods on so-called feature phones, not smartphones such as Android devices or iPhones. The reason, they said, is that feature phones still are far more prevalent in most of the world than smartphones are, so the target area is much larger."
I tend to hang onto all of my stuff until it breaks beyond repair or is no longer functional for me. I hung on to my Dell Dimension 8100 and kept it going with upgrades and replacements for almost 10 years. It's still usable, but I needed more computing power for number crunching so I got a new computer.
I used my Tungsten T3 for 4 years until it accidentally got washed in the laundry. Replaced it with another one and still using it 3 years later.
still watch tv on a 10 year old 23" CRT
I was switching between classes when I heard a friend of mine say the shuttle just blew up. I thought he was just bull-shitting and went on with my day. Then I got home from school and saw all the news coverage. It was a sad day after that.
I've used GeneWeb and really liked it. Written in OCaml, but appears to be dormant. Nothing much has happened with it for a few years now. Still a pretty good program though.
I don't see a trial version of this on the Bundle site....?
I'd likely pay more money if I knew I liked the games and would play them...but if I was buying sight unseen..I'd be a bit hesitant to put out more than $10 or so...
All the games have demo versions available if you visit the website for the game itself (they're linked to from the Humble Bundle site)
seriously, this is pretty old. physicists working in metrology have been working to redefine the kilogram for at least the last few decades
Does anybody not see irony in this? Amazon originally started off as an online retailer/clearinghouse helping people purchase hard to find books through affiliated second hand book sellers.
Playing devil's advocate, is it really so bad though? initial "bottom feeder" reaction aside, the thrift store/used book seller makes a sale and presumably makes a little profit, scanner guy posts a listing, makes a sale and some profit, book buyer gets a book they're after. Scanner guy just becomes a middle man, the same way Amazon started off.
That said, I'll stick with my initial bottom feeder reaction and agree with what backwardmechanic said.
Stewart's Calculus (1st ed) still remains on my bookshelf 20+ years after I took my 2 years of undergrad calculus. Even back then it was an expensive text, but was the only one I needed to purchase for 4 calculus courses. It also served me well through the rest of my undergrad and Master's degree. It was one of a handful of textbooks I kept following my Great Textbook Purge of 2007 and I still use it on a regular basis. I've definitely gotten my money's worth out of it.
This is all moot because the world will end in 2012 anyway
it's on the internet, so it must be true.
but if it happens that nothing happens in 2012, i'm sure someone will say there was a slight error in the calculations and say the asteroid will cause the end of the world. after all, what's a couple hundred years on a time scale of thousands of years?
Pay a visit to the library of a nearby university with a CS department (sometimes the departments have their own libraries) and look at the computer science related journals they have (a list of ACM associated journals can be found at http://www.acm.org/publications/panel/journals). Most of what I know about writing papers comes from reading them. The first thing you'll want to do is a literature search on related algorithms, and dig up some of those papers. Read through a bunch of them to see how they're organized, the types of subject material covered (to help you decide which journal to submit to) and the Information for Authors section. The Info for Authors section will tell you everything you need to know about formatting and submitting to that particular journal.
One of the staff librarians can probably help you find material to help you learn about the mechanics of paper writing.
The process from submission to publication (assuming your paper is accepted) will likely take several months to a year and involve one or more revisions.
I bought an HP LJ1012 over 5 years ago for $125. It's an inexpensive low-medium workload printer that works just fine for the small amount of printing I do. I go through a toner cartridge (~$70) every 1-2 years. As others have mentioned, it's pretty easy to find a laser printer for less than $100 these days.
Proton beam therapy is a logical extension of what's already being used. Electron beam therapy is already fairly common and the evolution to protons, with much higher LET (linear energy transfer) and Bragg peak, is just the next step. IANATP (I Am Not a Therapy Physicist) but I wouldn't think the side effects are much worse than conventional (x-ray or electron) therapy treatments and possibly a little less.
For the past few years, Philips has been lagging behind the technology curve when it comes to CT scanners. They're hardly the first to come out with a 256 slice scanner. FTA, the only new thing I see that Philips has brought is the faster rotation time (4 rotations/sec compared to 3 rotations/sec current scanners are capable of).
Actually, OCR is a considerably easier problem than creating a reliable CAD (Computer Aided Diagnosis) system.
There's a lot of research going on in CAD. However, creating a reliable CAD system is far from trivial, and the ones that are currently in clinical use are very task specific and are never used as the primary diagnostic tool. CAD systems are normally used to highlight areas for the radiologist to examine a little more closely. AFAIK, in the US the only CAD systems approved by the FDA are in mammography and do a reasonably good job at finding calcifications, but suck at finding masses. Lots of work going on in CAD for lung masses, but still research.
The type of CAD system you're envisioning is still a long, long way off.
Low field 0.5T magnets found in many stand-alone imaging centers and ortho clinics might be in the $500k-$1M range, but the more typical 1.5T magnet found in hospitals is usually considerably more expensive, with 3T magnets around the $3-4M range.