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The Gander – 18 February 2016

Another dimension

Researchers in Japan have successfully developed a low-cost human organ model production technique for use with 3D printers.

Developed in conjunction with the Dai Nippon Printing Co, the model will make the technology more affordable to allow more physicians to examine complicated interior organ structure.

It is hoped that the new technique will lead to the promotion of clinical site applications and enable the production of 3D human organ models at costs 33 per cent lower than the currently-available technology.

The news was reported recently in Science Daily.

 

Stress and memory loss

A new study by a team at the University of Iowa, US, has shown a potential link between stress hormones and short-term memory loss in older adults. While short-term boosts in cortisol levels are critical for alertness and problem-solving, the researchers found that prolonged and abnormally-high levels are associated with short-term memory loss in older people.

Previous research has shown cortisol to produce similar deleterious effects in other regions of the ageing brain, however this study was the first to specifically assess its impact on the prefrontal cortex.

The results raise the possibility that short-term memory decline in ageing adults can be curtailed or prevented by treatments that decrease levels of cortisol in certain individuals, according to the authors.

“Stress hormones are one mechanism that we believe leads to weathering of the brain,” commented Prof Jason Radley, Assistant Professor in Psychology at the University of Iowa and author of the paper.

“Like a rock on the shoreline, after years and years it will eventually break down and disappear.”

Previous studies have shown that abnormally high or prolonged high levels of cortisol can lead to other health problems, including digestion problems, anxiety, weight gain and high blood pressure.

The research was published in the Journal of Neuroscience.

 

Seeing is not believing

Psychologists in the US have conducted research which they say indicates that information from our eyes and ears, and processed by the brain, is significantly inaccurate.

The team from UCLA College, US, looked at the ‘spacial localisation’ ability of the brain to accurately process the information it receives by using flashes of light and bursts of sound in a specially-designed environment that included screens and five loudspeakers.

Some 384 participants between the ages of 18 and 22 years were asked to identify 525 stimuli in a 45-minute test.

The participants performed poorly when asked to identify the position of the light sources (the lights were not as close to the centre of the screens as the participants thought) and they also significantly misjudged the distance of the sound sources.

Senior author Dr Ladan Sharms, Associate Professor of Psychology in UCLA College, said: “Our basic sensory representation of the world — how information from our eyes and ears is processed by neurons in the brain — is inaccurate.

“We tend to view our senses as flawless and think that to see is to believe, so it’s eye-opening to learn that our perceptions are flawed.”

Commenting on the previously-held conventional wisdom that millions of years of evolution had perfected human spatial perception, Dr Sharms commented: “We didn’t expect these spatial errors; they’re very counter-intuitive. Spatial localisation is one of the most basic tasks the brain performs, and the brain does it constantly.

“Maybe evolution has favoured high precision in the centre of the visual field. We are really good at localising and discriminating at high acuity in the centre of our vision, and that comes with the cost of making more errors at outer areas.”

Pointing out that the participants answered much more accurately when the flashes and noise were played simultaneously at the same location, Dr Sharms added: “The brain is wired to use information from multiple senses to correct other senses.

“The saying is true: ‘If you want to hear better, put your glasses on’.”

The study — which was the largest of its kind to test sensory biases — was published in PLOS Computational Biology.

 

Faster MS diagnosis

A new technique to use MRI scanners to search for evidence of multiple sclerosis (MS) in the brain has been successfully tested by researchers in the UK.

The team utilised a standard clinical MRI scanner to carry out a T2-weighted imaging process in order to able to reveal lesions in the brain’s white matter that are centred on a vein, which is a known indicator of MS.

MS can be difficult to diagnose because of its many symptoms and not all sufferers experience all of the symptoms, as well as the fact that the disease can progress at different rates.

Forty patients were enlisted from the Neurology Outpatients’ Department of Nottingham University Hospitals NHS Trust in the UK.

In the test cohort, all patients with MS had central veins in more than 45 per cent of brain lesions, while the rest had central veins visible in less than 45 per cent of lesions. The team, which is based at the University of Nottingham and Nottingham University Hospitals NHS Trust, then applied the same diagnostic rules to the second cohort and all the remaining patients were correctly categorised into MS or non-MS by the blinded observer. The process took less than two minutes per scan and the results may have diagnostic implications, as among patients with suspected MS referred to treatment clinics in the UK, fewer than 50 per cent are found to have the condition.

“We already knew that large research MRI scanners could detect the proportion of lesions with a vein in the brain’s white matter, but these scanners are not clinically available,” said lead author Dr Nikos Evangelou.

“So we wanted to find out whether a single brain scan in an NHS hospital scanner could also be effective in distinguishing between patients known to have MS and patients known to have non-MS brain lesions.

“We are excited to reveal that our results show that clinical application of this technique could supplement existing diagnostic methods for MS.”

The results were reported in the Multiple
Sclerosis Journal.

 

Conspiracy facts

A physicist working in cancer research, science writer and broadcaster, Dr David Robert Grimes, has created an equation which shows that if major conspiracies did exist, they would be discovered in just a few short years.

Dr Grimes calculated that hoax moon landings would have been revealed in three years and eight months; a climate change fraud in three years, nine months; a vaccination conspiracy in three years and two months; and a secret cure for cancer in three years and three months.

His calculations involved the maximum number of people who could take part in a conspiracy in order to maintain it. For it to last five years, the maximum was 2,521 people. To keep it undetected for more than a decade, fewer than 1,000 people can be involved — even a cover-up of a single event, requiring no more than silence from the conspirators, would fail if more than 650 people were accomplices.

“A number of conspiracy theories revolve around science,” he said in PLOS One. “While believing the moon landings were faked may not be harmful, believing misinformation about vaccines can be fatal. However, not every belief in a conspiracy is necessarily wrong — for example, the Snowden revelations confirmed some theories about the activities of the US National Security Agency.

“It is common to dismiss conspiracy theories and their proponents out of hand but I wanted to take the opposite approach, to see how these conspiracies might be possible.

To do that, I looked at the vital requirement for a viable conspiracy — secrecy.”

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