There may be more to dyslexia than trouble with reading.
People with dyslexia sometimes see words and letters as scrambled, making reading a difficult task. Now a new study shows that dyslexia isn’t just a visual disturbance. It also appears to be a problem with the way the brain interprets sounds, particularly speech.
The study appears in the journal Neuron.
French researchers mapped the brain activity of 23 people with dyslexia and 21 people without the disorder as they listened to a white noise.
In order to understand the information in speech, the brain needs to be able to sync to the same frequency as the sounds it hears. The syncing of brain waves with sounds is called entrainment.
When the brain is properly entrained with a sound, it can correctly separate and interpret the signal, almost like breaking a code.
Researchers found that people without dyslexia had no trouble tuning their brains to the same frequencies as they heard in the white noise.
People with dyslexia, on the other hand, could not. Their brains had trouble syncing with sounds in the range of about 30 hertz, a frequency that’s important for understanding and decoding speech.
The dyslexic brain also appeared to be hyper-responsive to higher-frequency sounds.
This disrupted sound processing may help explain why people with dyslexia have trouble remembering and processing words and speech, says researcher Anne-Lise Giraud, a scientist with the Auditory Language Group at the Ecole Normale Superieure in Paris.
Study Signals ‘Progress’
Other experts who reviewed the study for WebMD said it offered important clues about the brain’s role in the often frustrating and debilitating condition.
“This is important information,” says Ken Pugh, PhD, who directs the Yale Reading Center in New Haven, Conn. “It’s progress.”
“This suggests a problem in the auditory cortex on the left side of the brain is making it difficult to perceive speech,” says Pugh, who is also the president and director of research at Yale’s Haskins Laboratories, which focuses on the biology of speech and language.
“That, in turn, might make it difficult to build an understanding of speech sounds that you need to have in order to learn to read,” he says.
In a move that demonstrates Apple’s determination to create an ever lighter Macbook that is also more environmentally friendly, the company has applied for two different patents that describe ways to use a fuel cell to power a portable computing device, which could of course also include devices like an iPad. In the patent applications, Apple also took the unusual step of adding some bit of political discourse to underscore its motivations in trying to build portable computing devices that are not reliant on fossil fuels.
Fuel cells are of course, a means for generating electricity by pushing compressed hydrogen though a membrane and mixing it with oxygen in the air. The only other output is water. It’s a technology that has been widely proposed as an alternative means for powering cars and trucks, but thus far, has not caught on to the extent that some had hoped.
In these latest patent filings, Apple is proposing a fuel cell that can be integrated directly into a portable device, rather than, as other’s have proposed, a means of charging it. Thus, the device would never need recharging at all, instead it would need a have its recyclable fuel cartridges refilled. The patent diagrams also show that the design for such a system that would also employ a small rechargeable a battery that would be charged by the fuel cell, but could also send a charge back to run the fuel cell. Such a system could in theory run for days, or even weeks before having to replace the fuel cartridge.
One of the major stumbling blocks for implementation of widespread fuel cell technology is the lack of an infrastructure to support it. If Apple were to sell hydrogen fuel cell powered Macbooks, they would also have to develop a means for creating the fuel to fill the cartridges and for selling them through their Apple stores, which they likely are investigating as well.
Not mentioned in the patent application is what Apple would do with the very small amount of water that the fuel cell would produce. Cleary simply pumping it out the bottom of a Macbook wouldn’t work, and storing it would add weight. They might also be working on a way to force it to evaporate, but that might be subject to environmental humidity levels. In any case, it’s clear that Apple understands the hurdles it faces as was also noted in the patent applications by the authors discussing how it is “extremely challenging” to figure out a way to create a hydrogen fuel cell system that would be both portable and in the end, cheap enough that the resulting device would still be price competitive. Thus, a fuel cell based Macbook likely is still a ways off into the future.
Findings support current recommendations to focus surveillance biopsies in the left colon.
Patients with chronic ulcerative colitis (UC) are at excess risk for both colorectal cancer and dysplasia — both of which occur most frequently in the left colon. Therefore, experts suggest that endoscopists conduct extensive biopsies in the left colon during surveillance colonoscopy. Now, researchers have retrospectively studied progression of low-grade dysplasia (LGD) to advanced neoplasia according to location in the colon among 121 patients with UC.
LGD was distal to the splenic flexure in 68 patients and proximal in 53. Eight patients progressed to high-grade dysplasia and seven to colorectal cancer during a median follow-up of 37.5 months. In 14 of these 15 patients, the more advanced lesion was found on the same side of the colon as the LGD. Thirteen patients had distal and 2 had proximal LGD (P=0.019). Fewer patients with distal LGD remained progression free after 5 years than patients with proximal dysplasia (75% vs. 95%). With regard to lesion morphology, LGD was raised in 89 patients and flat in 29 patients. Flat, distal LGD was four times more likely to progress to high-grade dysplasia or cancer than all other types (hazard ratio, 4.1).
Comment: Although this study has some design flaws, its results suggest that flat, distal LGD is a predictor of progression to more-advanced neoplasia. The reasons for this are unclear but could indicate that field defects in the distal colon are larger or that left-sided inflammation tends to be more severe and of longer duration. This finding also partly reflects that most of the raised dysplasia represented sporadic adenomas instead of true dysplasia-associated lesions or masses. Although these data strengthen recommendations to concentrate more biopsies in the left colon during surveillance colonoscopy, they are too preliminary to warrant varying recommendations of surveillance intervals for distal versus proximal LGD.
source: Journal Watch Gastroenterology
In a large study, 1 in 2000 adult patients died within 7 days after ED discharge. Predictors of death included increasing age, noninfectious lung disease, and renal disease.
To determine the rate and predictors of death within 7 days after emergency department (ED) evaluation in adults, researchers studied data from the Kaiser Permanente system in Southern California and government databases.
During 2007 through 2008, there were 728,312 discharges of 475,829 patients and 357 deaths. The rate of death within 7 days of ED discharge was 0.05%. The major risk factor for death was older age: patients aged 80 had nearly 11 times the odds of death relative to those aged 18–39. Comorbid diseases that were strong predictors of death included noninfectious lung disease (odds ratio 7.1), renal disease (OR, 5.6), ischemic heart disease (OR, 3.8), neoplasm (OR, 3.7), and diseases of the blood (OR, 3.6).
Comment: Although the overall 0.05% rate of death within 7 days of discharge seems high, many deaths occurred in older patients and those with severe chronic disease. For example, by our calculations, 0.46% of patients aged 80 died versus 0.01% of those aged 18–39, and 0.4% of those with renal disease died versus none of those with pregnancy and childbirth-related problems. These unsurprising findings suggest that early and assured follow-up is important in high-risk groups, especially patients older than 80.
source: Journal Watch Emergency Medicine