Comment

Comment by Dr. Krishna Kumari Challa on August 5, 2016 at 9:13am

Transfer of mitochondria from astrocytes to neurons after stroke

Under duress, nerve cells get a little help from their friends. Brain cells called astrocytes send their own energy-producing mitochondria to struggling nerve cells. Those gifts may help the neurons rebound after injuries such as strokes, scientists propose in the July 28 Nature.

It was known that astrocytes — star-shaped glial cells that, among other jobs, support neurons — take in and dispose of neurons’ discarded mitochondria. Now it turns out that mitochondria can move the other way, too. This astrocyte-to-neuron transfer is surprising.
Mitochondria produce the energy that powers cells in the body. Scientists have spotted the organelles moving into damaged cells in other parts of the body, including the lungs, heart and liver. The new study turns up signs of this mitochondrial generosity in the brain.

Not only do the mitochondria make it into neurons, they actually help. Neurons with donated mitochondria better survived their starvation diet. When grown in dishes without extra mitochondria floating around, neurons were less able to weather the poor conditions, the researchers found.

Further experiments suggest that the transfer happens not just in lab dishes, but in the brains of mice. A day after mice received a strokelike injury, astrocyte-produced mitochondria showed up inside their neurons. The gift giving seems to depend on a protein called CD38, which sits on the outside of astrocytes and may detect distress signals. When CD38 wasn’t functioning, the mice had fewer mitochondria in their neurons. What’s more, the mice were worse at balancing on wires than mice with normal CD38 behavior, a deficit that may be linked to having too few mitochondria in neurons.

The results bolster the idea that mitochondria donations between cells may have tremendous therapeutic potential

http://www.nature.com/nature/journal/v535/n7613/full/nature18928.html

Comment by Dr. Krishna Kumari Challa on August 5, 2016 at 9:00am

Neonicotinoid insecticides become inadvertent insect contraceptives!

Over the last year, beekeepers in some parts of the world  lost nearly half of their honeybee hives. And there are a lot of suspected culprits for this so-called beepocalypse—from parasitic mites, to viruses, to simple land use changes. But a recent study pointed to another possibility: poor sperm quality among the drone bees, leading to colony crashes. And now another group of researchers may have found a reason for the subpar sperm: neonicotinoid pesticides. These substances contain chemicals similar to nicotine and affect insect nervous systems. 

"So for the drones that were exposed to pesticides during development, it appears there were more dead sperm in their reproductive tracts." 

Williams and his colleagues studied the effects of two neonicotinoid pesticides on honeybee drones, genetically assigned to mate with queens. 

But in 20 honeybee hives Williams and his collaborators found that those drones exposed to standard environmental levels of the pesticides were shorter-lived, thus having fewer opportunities to mate. And even if the drones did survive, they had nearly 40 percent fewer living sperm than did control bees—meaning the pesticides were acting like honeybee contraceptives. 

http://rspb.royalsocietypublishing.org/content/283/1835/20160506

Comment by Dr. Krishna Kumari Challa on August 5, 2016 at 8:32am

Io’s Atmosphere Collapses
Jupiter's shadow makes this volcanic moon's atmosphere freeze solid once per day
Jupiter's active moon Io has a collapsible atmosphere: New views show the satellite's shroud of sulfur dioxide freezing when Io enters its planet's shadow each day and converting back to gas when the moon emerges.
Io, Jupiter's fifth moon, is the solar system's most volcanically active body; plumes of the sulfur dioxide gas bursts from multiple active volcanoes, reaching up to 300 miles (480 kilometers) above the moon's surface at a scalding 3,000 degrees Fahrenheit (1,650 degrees Celsius). The Jupiter moon's surface, on the other hand, is frigidly cold, and gets even colder when Jupiter blocks out the sun—which prompts the atmospheric collapse.

Io's atmosphere is in a constant state of collapse and repair, and shows that a large fraction of the atmosphere is supported by sublimation of sulfur dioxide ice

Comment by Dr. Krishna Kumari Challa on August 3, 2016 at 9:27am

What factors affect contact lens discomfort? Optometry and Vision Science presents research update.

up to 50 percent of contact lens wearers experience dryness or discomfort at least occasionally. New research aimed at understanding and managing this common and complex problem is presented in the special August issue of Optometry and Vision Science, official journal of the American Academy of Optometry. The journal is published by Wolters Kluwer.

http://www.eurekalert.org/pub_releases/2016-08/wkh-wfa080116.php

Comment by Dr. Krishna Kumari Challa on August 2, 2016 at 7:46am

Comment by Dr. Krishna Kumari Challa on July 30, 2016 at 5:04am

Graphene-based sheets make dirty water drinkable simply and cheaply!
Engineers at the Washington University in St. Louis (WUSTL) have developed graphene-based biofoam sheets that can be laid on dirty or salty dams and ponds to produce clean drinking water, using the power of the sun. This new technique could be a cheap and simple way to help provide fresh water in countries where large areas of water are contaminated with suspended particles of dirt and other floating matter.

The biofilm is created as a two-layered structure consisting of two nanocellulose layers produced by bacteria. The lower layer contains pristine cellulose, while the top layer also contains graphene oxide, which absorbs sunlight and produces heat. The system works by drawing up water from underneath like a sponge where it then evaporates in the topmost layer, leaving behind any suspended particulates or salts. Fresh water then condenses on the top, where it can be drawn off and used.

The results of this research were recently published in the journal Advanced Materials.

Source: Washington University in St.Louis

Comment by Dr. Krishna Kumari Challa on July 29, 2016 at 7:35am

Open-source drug discovery a success
Researchers from around the world collaborate
In what is being called the first-ever test of open-source drug-discovery, researchers from around the world have successfully identified compounds to pursue in treating and preventing parasite-borne illnesses such as malaria as well as cancer.

Starting in late 2011, the Medicines for Malaria Venture, based in Geneva, Switzerland, distributed 400 diverse compounds with antimalarial activity free of charge to 200 labs in 30 countries. One-third of the labs reported their results in a paper published today in PLOS Pathogens, "Open source drug discovery with the Malaria Box compound collection for neglected diseases and beyond."

The results have ignited more a dozen drug-development projects for a variety of diseases.

"The trial was successful not only in identifying compounds to pursue for anti-malarials, but it also identified compounds to treat other parasites and cancer," said lead author Wesley Van Voorhis. To help lead the project, Van Voorhis took a sabbatical from his roles as a University of Washington professor of medicine (allergy and infectious diseases) and director of the Center for Emerging and Re-emerging Infectious Diseases.

The National Cancer Institute is now working on a colon cancer drug that emerged from the testing, Van Voorhis said. Several European labs are working on anti-worm compounds, and numerous U.S. labs are investigating drugs to combat other parasites. Medicines for Malaria Venture is also working with pharmaceutical companies GSK and Novartis on related anti-malarials, he added.

In their paper, researchers cited the lack of interaction between academia and industry as a major curb to innovation in drug discovery.
Much of the global resource in biology is present in universities, whereas the focus of medicinal chemistry is still largely within industry. Open-source drug discovery, with sharing of information, is clearly a first step towards overcoming that gap," they wrote.

The Malaria Box distributed 400 diverse druglike molecules that were most often found in industry collections, helping to bridge the gap between industry and academia.

This open-access effort was so successful that Medicines for Malaria Venture has begun to distribute another set of compounds with broader potential applicability, called the Pathogen Box. The box is available now to scientific labs globally.
Source: UNIVERSITY OF WASHINGTON HEALTH SCIENCES/UW MEDICINE

Comment by Dr. Krishna Kumari Challa on July 27, 2016 at 8:10am

Researchers in China and the UK have attempted to define and measure human intelligence and discover how intellect works. The research team, which includes researchers from Fudan University, quantified the brain’s dynamic functions and identified how different parts of the brain interact with each other at different times. The work was published in Brain. Using resting-state magnetic resonance imaging analysis on thousands of people’s brains around the world, the research has found that the areas of the brain that are associated with learning and development show high levels of variability, meaning that they change their neural connections with other parts of the brain more frequently—over a matter of minutes or seconds. On the other hand, regions of the brain that aren’t associated with intelligence—the visual, auditory, and sensory-motor areas—show small variability and adaptability. What the researchers found was that the more variable a brain is, and the more its different parts frequently connect with each other, the higher a person’s IQ and creativity are.
http://brain.oxfordjournals.org/content/139/8/2307

Comment by Dr. Krishna Kumari Challa on July 23, 2016 at 9:45am

How bees cool their homes...
When a honeybee colony gets hot and bothered, the crisis sets tongues wagging. Middle-aged bees stick their tongues into the mouths of their elders, launching these special drinker bees to go collect water. That’s just one detail uncovered during a new study of how a colony superorganism cools in hot weather.
Honeybees communicate about collecting water and work together in deploying it as air-conditioning. The tests show just how important water is for protecting a colony from overheating.
Bees often get as much water as they need in the nectar they sip. But they do need extra water at times, such as during overheating in the center of the nest where eggs and young are coddled. When researchers artificially heated that zone in two colonies confined in a greenhouse, worker bees fought back. They used their wings to fan hot air out of the hive. “You can put your hand in the opening of a hive on a hot day and feel the blast of air that’s being pushed out.
Several hundred bees also move out of the nest to cluster in a beardlike mass nearby. Their evacuation reduces body heat within the nest and opens up passageways for greater airflow.
The bees also had a Plan C — evaporative cooling. Middle-aged bees inside a hive walked toward the nest entrance to where a small number of elderly bees, less than 1 percent of the colony, hang out and wait until water is needed.
http://jeb.biologists.org/content/219/14/2156.abstract

Comment by Dr. Krishna Kumari Challa on July 23, 2016 at 9:03am

A family of related, exotic particles, each made up of four quarks, has been discovered. The finding could hold clues about the evolution of the universe, the researchers said.

The four newfound tetraquarks, now called X(4140), X(4274), X(4500) and X(4700), each are composed of two quarks and two antiquarks (the antimatter partners of quarks). Yet each of the newfound particles has a different mass and different subatomic properties. They are considered a family of tetraquark siblings because of having the same quark composition and arrangement.

Quarks are elementary particles, the building blocks of protons and neutrons. Until the recent discoveries of tetra and even pentaquarks, physicists thought quarks grouped only into pairs or triplets. The newfound tetraquark family is even more distinct because the family members are made up of heavy, exotic types of quarks — known as charm quarks and strange quarks — which are not found in everyday materials.
Skwarnicki and Britton detailed their discoveries in the June issue of the journal Physical Review Letters.

http://arxiv.org/abs/1606.07898

• ‹ Previous
• 1
• …
• 648
• 649
• 650
• 651
• 652
• …
• 853
• Next ›
• Page