Please create an account to participate in the Slashdot moderation system

 



Forgot your password?
typodupeerror
Note: You can take 10% off all Slashdot Deals with coupon code "slashdot10off." ×

Comment prototyping for devices in magnetic fields (Score 2) 266

Part of my job is to design objects that will be used in a high-magnetic field environment, namely MRI scanners. Metal is not an option for me. Prototyping with traditional methods (e.g., CNC machining) is extremely cost-prohibitive. So I use 3D-printing. Some I do in-house with an FDM machine, in ABS. A lot I outsource to a better printer that can use other materials, say polycarb, or other methods, like laser sintering. At the end of the day, I get functional prototypes that I can check for utility, than design molds for injection-molded parts based on feedback from those prototypes. 3D printing enables me to do this part of my job. Without it, there would be no prototyping, due to cost, and thus no objects in the magnetic field. Truly a gamechanger.

Comment Structural MRI? (Score 1) 138

I'd love to read the original article. I am not sure how they detected structure, but fMRI most certainly was not it. If fMRI was used, then it can only be a functional difference, there is no way to observe a structural change with fMRI unless it is something gross (like a 5x5x5mm cube of brain tissue suddenly went missing). If T2-weighting was used, then one is still limited to fairly gross changes (lets say a cube that is 1 mm^3 in volume). Finally, we arrive at the various diffusion MRI techniques, which have no established ground truth, but whose models can provide sub-voxel resolution. Not enough information to really evaluate in the OP.

Comment Re:Didn't you Know? (Score 4, Insightful) 342

The people writing the checks need to better understand that these scientists are the main reason that the US economy does as well as it does. We have had and to date maintain a significant advantage over other nation states in terms of our technological innovation. However, it is undeniable that other countries are fast catching up. Our technological advantage is not a given thing, we have to properly fund R&D for it to be maintained. Technological prowess leads to economic health.

Comment Re:What am I missing here? (Score 3, Insightful) 223

Think of photons as the central point from which oscillating magnetic and electric fields originate. And that this point moves through space at ~3x10^8 m/s. It is kind of like throwing two stones into water and watching the resulting interference patterns, excepts that the centers of those patterns are moving instead of stationary. Hence, collision isn't really an apt description.

Comment Spectroscopy with MRI (Score 3, Informative) 23

Disclaimer: I am a physicist who works in MRI. MRI can be used to measure concentrations of certain biochemicals. MRI is sensitive enough to different proton-containing species that the frequency difference between fat and water causes image artifacts that can pose great difficulty. Not all biomolecules are sufficiently concentrated in the brain, or have a spectrum that is unique enough to be measured in vivo. A good example of a brain chemical that can be measured is N-acetyl aspartate (NAA), which has a proton peak at around 2 ppm that doesn't overlap with much else. Magnetic resonance spectroscopy is very difficult, and is most easily accomplished on research scanners operating at 3 tesla or higher. The reason for this is that rather than letting all hydrogen nuclei contribute to one signal that is then spatially located, one must parse what kinds of nuclei (i.e. what their chemical shift is) within each voxel. This not only imposes technical difficulties, but reduces the signal to noise ratio, potentially requiring more signal averaging in order to see sufficient signal above the noise floor.
Image

Students Banned From Bringing Pencils To School 426

mernilio writes "According to UPI: 'A Massachusetts school district superintendent said a memo banning sixth graders from carrying pencils was written without district approval. North Brookfield School District interim Superintendent Gordon Noseworthy said Wendy Scott, one of two sixth-grade teachers at North Brookfield Elementary School, did not get approval from administrators before sending the memo to all sixth-grade parents, the Worcester Telegram & Gazette reported Thursday. The memo said students would no longer be allowed to bring writing implements to school. It said pencils would be provided for students in class and any students caught with pencils or pens after Nov. 15 would face disciplinary action for having materials 'to build weapons.'"
Image

US Embassy Categorizes Beijing Air Quality As 'Crazy Bad' 270

digitaldc writes "Pollution in Beijing was so bad Friday the US embassy, which has been independently monitoring air quality, ran out of conventional adjectives to describe it, at one point saying it was 'crazy bad.' The embassy later deleted the phrase, saying it was an 'incorrect' description and it would revise the language to use when the air quality index goes above 500, its highest point and a level considered hazardous for all people by US standards. The hazardous haze has forced schools to stop outdoor exercises, and health experts asked residents, especially those with respiratory problems, the elderly and children, to stay indoors."

Comment Re:Ohio University Press Release is Misleading (Score 1) 97

Ohio STATE University. Not Ohio University. There is a huge world of difference. And PR is important, relying on the general media to disseminate information from original scientific journal articles doesn't work. Scientists should be the ones presenting their work, not journalists who are at best mildly fluent in the research areas they cover.
Image

Happy Towel Day 122

An anonymous reader writes "While Douglas Adams continues his attempt to set a new record for the longest extended lunch break, geeks all over the universe pay tribute to the beloved author by celebrating the tenth edition of Towel Day. Towel Day is more alive than ever. This year Richard Dawkins, one of Adams' best friends, has tweeted a Towel Day reminder to his numerous followers. The CERN Bulletin has published an article on Towel Day. There has been TV coverage and there will be a radio interview. The Military Republic of the Deltan Imperium, a newly formed micronation, has recognized Towel Day as an official holiday. In Hungary several hundreds of hitchhiker fans want to have a picnic together in a park. And there's a concert, a free downloadable nerdrap album, a free game being released, the list goes on and on."
Mars

Mars Images Reveal Evidence of Ancient Lakes 128

Matt_dk writes "Spectacular satellite images suggest that Mars was warm enough to sustain lakes three billion years ago, a period that was previously thought to be too cold and arid to sustain water on the surface, according to research published today in the journal Geology. Earlier research had suggested that Mars had a warm and wet early history but that between 4 billion and 3.8 billion years ago, before the Hesperian Epoch, the planet lost most of its atmosphere and became cold and dry. In the new study, the researchers analysed detailed images from NASA’s Mars Reconnaissance Orbiter, which is currently circling the red planet, and concluded that there were later episodes where Mars experienced warm and wet periods."
Image

Scientists Say a Dirty Child Is a Healthy Child 331

Researchers from the School of Medicine at the University of California have shown that the more germs a child is exposed to, the better their immune system in later life. Their study found that keeping a child's skin too clean impaired the skin's ability to heal itself. From the article: "'These germs are actually good for us,' said Professor Richard Gallo, who led the research. Common bacterial species, known as staphylococci, which can cause inflammation when under the skin, are 'good bacteria' when on the surface, where they can reduce inflammation."

Most public domain software is free, at least at first glance.

Working...