Classroom

1. Forming Memories

The birth of a memory, the split second when the human brain encodes an event for future reference, has been captured through sophisticated neuroimaging and used to predict accurately whether a specific experience will later be remembered or forgotten, according to research published in the Aug. 21 issue of the journal Science.

Based on collaborative research by scientists at the Massachusetts General Hospital (MGH)-NMR Center in Boston, Washington University in St. Louis and Harvard University (all in USA) the article describes how levels of activity in certain brain structures involved in processing verbal information can predict whether that information will be retained in memory.

This study marks the first time that scientists have been able to peer inside someone’s brain and predict on average whether or not the brain will forget something being experienced later. Scientists can actually see areas of the brain as they go about the process of memorization.

Although psychologists have long suspected that how we process information into memory is critically important to later remembering and forgetting, this study is the first to capture images of specific memories as they are being formed within the brain.

This study provides a firmer biological underpinning for the concept that how we encode information is key to whether or not it is remembered. It is the first work to tie the creation of a specific verbal memory to specific levels of activity in certain areas of the brain.

One of the structures showing increased activity in verbal memory formation is the left parahippocampal gyrus, a main input pathway to the hippocampus, a part of the brain that has long been recognized as crucial for storing and retrieving memories. The authors note that, while this area previously had been implicated in processing unfamiliar experiences, this study suggests the parahippocampal gyrus plays a broader role in memory formation. Even when experiences are similarly novel, differences in parahippocampal activity were seen that predict future memory.

 

2. Climate Change due to black carbon soot

In addition to causing smoggy skies and chronic coughs, soot — or black carbon — turns out to be the number two contributor to global warming. It’s second only to carbon dioxide, according to a four-year assessment by an international panel.

The new study concludes that black carbon, the soot particles in smoke and smog, contributes about twice as much to global warming as previously estimated, even by the 2007 Intergovernmental Panel on Climate Change.

The silver lining may be that controlling these emissions can deliver more immediate climate benefits than trying to control carbon dioxide.

The paper was made freely available online Jan. 15 in the Journal of Geophysical Research-Atmospheres.

Some previous research had hinted that models were underestimating black-carbon emissions from such things as open burning of forests, crops and grasslands, and from energy-related emissions in Southeast Asia and East Asia.

Black carbon’s role in climate is complex. Dark particles in the air work to shade Earth’s surface while warming the atmosphere. Black carbon that settles on the surface of snow and ice darkens the surface to absorb more sunlight and increase melting. Finally, soot particles influence cloud formation in ways that can have either a cooling or warming impact.

The report surveyed past studies and included new research to quantify the sources of black carbon and better understand its overall effect on the climate.

While carbon dioxide has a half-life of 100 years, black carbon stays in the atmosphere for only a few days.

The researchers investigated various sources of black carbon to see which reductions might have the most short-term cooling impact. Regulating emissions from diesel engines followed by replacing some wood- and coal-burning household stoves, authors find, would have the greatest immediate cooling impact.

Black carbon contributes to climate change in the mid to high latitudes, including the northern United States, Canada, northern Europe and northern Asia, as well as affecting rainfall patterns of the Asian Monsoon.

3. Remnants of 1500 km long Martian river

Pictures by the European Space Agency have revealed a 1500 km long and 7 kilometre wide river that once ran across Mars.

The agency’s Mars Express imaged the striking upper part of the remnants of Reull Vallis river on Mars with its high-resolution stereo camera.

New analogies are giving planetary geologists tantalising glimpses of a past on the Red Planet not too dissimilar to events on our own world today.

Reull Vallis, is believed to have formed when running water flowed in the distant martian past, cutting a steep-sided channel through the Promethei Terra Highlands before running on towards the floor of the vast Hellas basin.

This sinuous structure, which stretches for almost 1500 km across the martian landscape, is flanked by numerous tributaries, one of which can be clearly seen cutting in to the main valley towards the upper (north) side.

The new Mars Express images show a region of Reull Vallis at a point where the channel is almost 7 km wide and 300 m deep. The sides of Reull Vallis are particularly sharp and steep, with parallel longitudinal features covering the floor of the channel itself.

The structures were formed long after it was originally carved by liquid water during the Hesperian period, which is believed to have ended between 3.5 billion and 1.8 billion years ago.

4. Harvesting Energy from Water Vapor

MIT (USA) engineers have created a new polymer film that can generate electricity by drawing on a ubiquitous source: water vapor.

The new material changes its shape after absorbing tiny amounts of evaporated water, allowing it to repeatedly curl up and down. Harnessing this continuous motion could drive robotic limbs or generate enough electricity to power micro- and nanoelectronic devices, such as environmental sensors.

5. Stress in Adolescence could be a cause for Mental Illness

Researchers at John Hopkins (USA) have established a link between elevated levels of a stress hormone in adolescence, a critical time for brain development and genetic changes that, in young adulthood, cause severe mental illness in those predisposed to it.

The findings, reported in the journal Science, could have wide-reaching implications in both the prevention and treatment of schizophrenia, severe depression and other mental illnesses.

6. Unlocking How Insulin Interacts With Cells

The discovery of insulin nearly a century ago changed diabetes from a death sentence to a chronic disease.

Today a team that includes researchers (USA) announced a discovery that could lead to dramatic improvements in the lives of people managing diabetes.

After decades of speculation about exactly how insulin interacts with cells, the international group of scientists finally found a definitive answer. In an article published January 9 in the journal Nature, the group describes how insulin binds to the cell to allow the cell to transform sugar into energy — and also how the insulin itself changes shape as a result of this connection.

These findings carry profound implications for diabetes patients. This new information increases exponentially the chances to develop better treatments — in particular, oral medications instead of syringes, pens or pumps.

(source: sciencedaily.com)

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