Comment Re:Laser Filters? (Score 1) 546
Comment Re:possible original source (Score 1) 117
Comment Re:Antibiotics? (Score 1) 117
And even if you wanted to "program" this feature, you'd have to deal with the nasty problem of protein folding in silico. Better to leave this entire process highly parallel in wetware.
there is no need to deal with protein folding in silico - we know a LOT about proteins and how they work just from standard biochemical assays. There are literally tens of thousands of characterized molecules with known DNA sequences from which we can pick and choose useful sets - slightly modify if need be - and then recombine in novel ways inside a cell. And we can do it directly - without having to rely on some kind of directed evolution - which is quite slow. It is very hard to program a specific well-defined program into a phage - whereas the molecular biology to add features, protein sequences and other regulatory DNA to E. coli is trivial at this point. This is not about making a better immune system, it is about making one (or something else) that is entirely characterized and programmed - not one that must undergo thousands of generations of (difficult to control for) selection in order to become useful.
...not to calculate anything fancy.
Again, because we can program any arbitrary code into the bugs, it is trivial to make a bacteria that lights up green when it detects particular chemicals. Or that only grow when you have a fever, or that do other similar calculations. There are of course extreme difficulties when you're talking about therapeutics because you're interacting with the human body. But outside the human body it is only a matter of time before you start seeing bacterial sensors on everything. They are cheap, they are robust, and they can enzymatically recognize certain properties that mechanical sensors may have great difficulty doing, or doing rapidly, or cheaply. And when you can link the sensors with a programmable logic, THEN you get the really cool stuff. This research demonstrates the first steps into getting the programmable logic up and running.
Comment Re:Antibiotics? (Score 1) 117
Once you have enough parts (that are found all over biology, and are slowly being annotated and dissected) you can start to create real computers.
This is very much about passing information between individuals. The 'logic' gates are very much still analogue - in that they are leaky and really only useful at a statistical level, but they are working. But small molecules can act as the medium of transmission between two different individual E. coli in a way that very much resembles a computation.
Comment Shanghai's Air Quality (Score 3, Informative) 133
http://www.envir.gov.cn/Eng/Airep/index.asp
Submission + - For-profit movie download sites threaten MPAA (yahoo.com)
Movie fans downloading free pirated films are no longer Hollywood's worst nightmare, but that's only because of a newer menace: cheap, and equally illegal, subscription services. Foreign, often mob-run, businesses aggregate illegally obtained movies into "cyberlockers" Cyberlocker-based businesses operate from Russia , Ukraine, Colombia, Germany, Switzerland and elsewhere. Hollywood movies are made available via illegal for-profit sites within days of theatrical release, while the advent of global releasing now allows the proliferation of individual titles into an array of language dubs within the first month of a theatrical debut, he noted. When movies are released on DVD and Blu-ray Disc, the sites upgrade the quality of video offered from camcorded images to pristine digital copies. "Sometimes these sites look better than the legitimate sites," Huntsberry said. "That's the irony."
For some reason, they also mention that the U.K. needs a DMCA even though the U.K. is not a problem in this case:
In the U.K., we are hamstrung by the fact that we have very weak legislation. However, the U.K. in April adopted the Digital Economy Act that mandates a so-called graduate response to cybertheft, similar to a plan used in France and elsewhere.
Just a though, but maybe, if they offered a low-cost, for-profit, legitimate download site without DRM, they could receive the profits and not the cyberlockers.
Comment The Scientist's Letter of Concern (Score 1) 357
We are writing to call your attention to serious concerns about the potential health risks of the recently adopted whole body backscatter X-ray airport security scanners. This is an urgent situation as these X-ray scanners are rapidly being implemented as a primary screening step for all air travel passengers.
Our overriding concern is the extent to which the safety of this scanning device has been adequately demonstrated. This can only be determined by a meeting of an impartial panel of experts that would include medical physicists and radiation biologists at which all of the available relevant data is reviewed.
An important consideration is that a large fraction of the population will be subject to the new X-ray scanners and be at potential risk, as discussed below. This raises a number of ‘red flags’. Can we have an urgent second independent evaluation?
The Red Flags
The physics of these X-rays is very telling: the X-rays are Compton-Scattering off outer molecule bonding electrons and thus inelastic (likely breaking bonds). Unlike other scanners, these new devices operate at relatively low beam energies (28keV). The majority of their energy is delivered to the skin and the underlying tissue. Thus, while the dose would be safe if it were distributed throughout the volume of the entire body, the dose to the skin may be dangerously high.
The X-ray dose from these devices has often been compared in the media to the cosmic ray exposure inherent to airplane travel or that of a chest X-ray. However, this comparison is very misleading: both the air travel cosmic ray exposure and chest X- rays have much higher X-ray energies and the health consequences are appropriately understood in terms of the whole body volume dose. In contrast, these new airport scanners are largely depositing their energy into the skin and immediately adjacent tissue, and since this is such a small fraction of body weight/vol, possibly by one to two orders of magnitude, the real dose to the skin is now high.
In addition, it appears that real independent safety data do not exist. A search, ultimately finding top FDA radiation physics staff, suggests that the relevant radiation quantity, the Flux [photons per unit area and time (because this is a scanning device)] has not been characterized. Instead an indirect test (Air Kerma) was made that emphasized the whole body exposure value, and thus it appears that the danger is low when compared to cosmic rays during airplane travel and a chest X-ray dose.
In summary, if the key data (flux-integrated photons per unit values) were available, it would be straightforward to accurately model the dose being deposited in the skin and adjacent tissues using available computer codes, which would resolve the potential concerns over radiation damage.
Our colleagues at UCSF, dermatologists and cancer experts, raise specific important concerns:
A) The large population of older travelers, >65 years of age, is particularly at risk from the mutagenic effects of the X-rays based on the known biology of melanocyte aging.
B) A fraction of the female population is especially sensitive to mutagenesis- provoking radiation leading to breast cancer. Notably, because these women, who have defects in DNA repair mechanisms, are particularly prone to cancer, X-ray mammograms are not performed on them. The dose to breast tissue beneath the skin represents a similar risk.
C) Blood (white blood cells) perfusing the skin is also at risk.
D) The population of immunocompromised individuals--HIV and cancer patients (see above) is likely to be at risk for cancer induction by the high skin dose.
E) The risk of radiation emission to children and adolescents does not appear to have been fully evaluated.
F) The policy towards pregnant women needs to be defined once the theoretical risks to the fetus are determined.
G) Because of the proximity of the testicles to skin, this tissue is at risk for sperm mutagenesis.
H) Have the effects of the radiation on the cornea and thymus been determined?
Moreover, there are a number of ‘red flags’ related to the hardware itself. Because this device can scan a human in a few seconds, the X-ray beam is very intense. Any glitch in power at any point in the hardware (or more importantly in software) that stops the device could cause an intense radiation dose to a single spot on the skin. Who will oversee problems with overall dose after repair or software problems? The TSA is already complaining about resolution limitations; who will keep the manufacturers and/or TSA from just raising the dose, an easy way to improve signal-to-noise and get higher resolution? Lastly, given the recent incident (on December 25th), how do we know whether the manufacturer or TSA, seeking higher resolution, will scan the groin area more slowly leading to a much higher total dose?
After review of the available data we have already obtained, we suggest that additional critical information be obtained, with the goal to minimize the potential health risks of total body scanning. One can study the relevant X-ray dose effects with modern molecular tools. Once a small team of appropriate experts is assembled, an experimental plan can be designed and implemented with the objective of obtaining information relevant to our concerns expressed above, with attention paid to completing the information gathering and formulating recommendations in a timely fashion.
We would like to put our current concerns into perspective. As longstanding UCSF scientists and physicians, we have witnessed critical errors in decisions that have seriously affected the health of thousands of people in the United States. These unfortunate errors were made because of the failure to recognize potential adverse outcomes of decisions made at the federal level. Crises create a sense of urgency that frequently leads to hasty decisions where unintended consequences are not recognized. Examples include the failure of the CDC to recognize the risk of blood transfusions in the early stages of the AIDS epidemic, approval of drugs and devices by the FDA without sufficient review, and improper standards set by the EPA, to name a few. Similarly, there has not been sufficient review of the intermediate and long-term effects of radiation exposure associated with airport scanners. There is good reason to believe that these scanners will increase the risk of cancer to children and other vulnerable populations. We are unanimous in believing that the potential health consequences need to be rigorously studied before these scanners are adopted. Modifications that reduce radiation exposure need to be explored as soon as possible.
In summary we urge you to empower an impartial panel of experts to reevaluate the potential health issues we have raised before there are irrevocable long-term consequences to the health of our country. These negative effects may on balance far outweigh the potential benefit of increased detection of terrorists.
Comment Re:And yet... (Score 1) 357
"Unlike other scanners, these new devices operate at relatively low beam energies (28keV). The majority of their energy is delivered to the skin and the underlying tissue. Thus, while the dose would be safe if it were distributed throughout the volume of the entire body, the dose to the skin may be dangerously high.
The X-ray dose from these devices has often been compared in the media to the cosmic ray exposure inherent to airplane travel or that of a chest X-ray. However, this comparison is very misleading: both the air travel cosmic ray exposure and chest X- rays have much higher X-ray energies and the health consequences are appropriately understood in terms of the whole body volume dose. In contrast, these new airport scanners are largely depositing their energy into the skin and immediately adjacent tissue, and since this is such a small fraction of body weight/vol, possibly by one to two orders of magnitude, the real dose to the skin is now high."
Comment Re:If the dose was calculated right, not a problem (Score 1) 357
Comment Re:Nobody cares (Score 1) 357
Comment Re:Sterilization....the easy way! (Score 1) 357
So yeah, your heart sees no more radiation than the trip into the air. But your neck, your eyes, your breasts if you have them, and your testicles if you have them all receive a great deal of local radiation - far more than would be considered safe for a routine examination. But the way the safety is 'calculated' by the people who designed the machine it looks okay on paper.