Science Simplified!

Comment

Comment by Dr. Krishna Kumari Challa on September 9, 2014 at 7:12am

Comment by Dr. Krishna Kumari Challa on September 6, 2014 at 6:16am

Synthetic Fabrics Host More Stench-Producing Bacteria

Micrococcus bacteria thrive on the open-air lattice of synthetic fibers—where they sit chomping on the fatty acids in our sweat, turning them into shorter, stinkier molecules.
http://aem.asm.org/content/early/2014/08/12/AEM.01422-14.full.pdf+h...

Comment by Dr. Krishna Kumari Challa on September 5, 2014 at 6:17am

Rabies races up nerve cells
Virus may speed to the brain by hitching a ride with a protein
Rabies Virus Hijacks and Accelerates the p75NTR Retrograde Axonal Transport Machinery
Abstract:
Rabies virus (RABV) is a neurotropic virus that depends on long distance axonal transport in order to reach the central nervous system (CNS). The strategy RABV uses to hijack the cellular transport machinery is still not clear. It is thought that RABV interacts with membrane receptors in order to internalize and exploit the endosomal trafficking pathway, yet this has never been demonstrated directly. The p75 Nerve Growth Factor (NGF) receptor (p75NTR) binds RABV Glycoprotein (RABV-G) with high affinity. However, as p75NTR is not essential for RABV infection, the specific role of this interaction remains in question. Here we used live cell imaging to track RABV entry at nerve terminals and studied its retrograde transport along the axon with and without the p75NTR receptor. First, we found that NGF, an endogenous p75NTR ligand, and RABV, are localized in corresponding domains along nerve tips. RABV and NGF were internalized at similar time frames, suggesting comparable entry machineries. Next, we demonstrated that RABV could internalize together with p75NTR. Characterizing RABV retrograde movement along the axon, we showed the virus is transported in acidic compartments, mostly with p75NTR. Interestingly, RABV is transported faster than NGF, suggesting that RABV not only hijacks the transport machinery but can also manipulate it. Co-transport of RABV and NGF identified two modes of transport, slow and fast, that may represent a differential control of the trafficking machinery by RABV. Finally, we determined that p75NTR-dependent transport of RABV is faster and more directed than p75NTR-independent RABV transport. This fast route to the neuronal cell body is characterized by both an increase in instantaneous velocities and fewer, shorter stops en route. Hence, RABV may employ p75NTR-dependent transport as a fast mechanism to facilitate movement to the CNS.
http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal...

Comment by Dr. Krishna Kumari Challa on September 5, 2014 at 6:15am

Removing both breasts may not boost cancer survival
Women diagnosed with cancer in one breast who choose to have both removed may have no better survival rates than women who opt for breast-conserving surgery and radiation. In a study of nearly 190,000 women, the 10-year mortality rate was 18.8 percent for women who had double mastectomies, 20.1 for those who had single mastectomies and 16.8 percent for women who had lumpectomies plus radiation, researchers report in the Sept. 3 JAMA. The slightly lower survival rate among women who had only one breast removed may be influenced by socioeconomic status and race and ethnicity, the researchers say.
http://jama.jamanetwork.com/article.aspx?articleid=1900512&resu...

Comment by Dr. Krishna Kumari Challa on September 5, 2014 at 6:13am

The Milky Way is part of a much vaster galactic network than previously thought. The galaxy drifts along in a stream of galaxies on the outskirts of a newly identified collection of galaxy clusters, a supercluster named Laniakea. This supercluster — whose name means “heaven immeasurable” in Hawaiian — holds the mass of 100 million billion suns within a region that spans about 520 million light-years.

Astrophysicist R. Brent Tully of the University of Hawaii in Honolulu and colleagues sifted through data describing the positions and velocities of over 8,000 galaxies to get a fresh look at the Milky Way’s place in space. After accounting for the motion caused by the expansion of the universe, the team created a three-dimensional view of how gravity molds the galaxy’s cosmic neighborhood.

The new map, published in the Sept. 4 Nature, reveals Laniakea’s boundaries and weblike framework. The Milky Way lies along one of the lines of that web, in a tributary feeding one of many galactic rivers. Those streams converge in a gravitational valley roughly 200 million light-years away near two massive galaxy clusters: Norma and Centaurus. Their combined gravity appears to be drawing in other galaxies and clusters within Laniakea, including the Milky Way.

Milky Way connected to a vast network of galaxies
Astronomers name home galactic supercluster Laniakea
http://www.nature.com/nature/journal/v513/n7516/full/nature13674.html

Comment by Dr. Krishna Kumari Challa on September 4, 2014 at 8:26am

What makes humans special?

Comment by Dr. Krishna Kumari Challa on September 4, 2014 at 8:06am

Conspicuous absences at global science advice meeting held recently.
The Science Advice to Governments conference, a gathering of scientists and science advisers from nearly 50 countries in Auckland, New Zealand: The conference explored how scientists should convey knowledge to policymakers, and what obstacles stand in their way. Discussions ranged from how to provide scientific input during humanitarian emergencies to how a country can effectively build science capacity.
However, there were no young scientists, women & scientists from most of the developing countries! And no politicians!There were several complaints. The gaps in representation at scientific conferences were, unfortunately, symptomatic of a wider problem. Although it would be beneficial to society to bring more women and young people from developing countries into the scientific community, they often have trouble breaking in because the “old boys’ network” is too quick to “discount” their work, which tends to explore new paradigms and use interdisciplinary approaches that challenge the status quo.
So?!
Let us think about the remedy.

Comment by Dr. Krishna Kumari Challa on September 3, 2014 at 7:32am

A study in rats suggests that eating junk food weakens self control, leading to overeating and obesity.
Cafeteria diet impairs expression of sensory-specific satiety and stimulus-outcome learning
http://journal.frontiersin.org/Journal/10.3389/fpsyg.2014.00852/abs...
A range of animal and human data demonstrates that excessive consumption of palatable food leads to neuroadaptive responses in brain circuits underlying reward. Unrestrained consumption of palatable food has been shown to increase the reinforcing value of food and weaken inhibitory control; however, whether it impacts upon the sensory representations of palatable solutions has not been formally tested. These experiments sought to determine whether exposure to a cafeteria diet consisting of palatable high fat foods impacts upon the ability of rats to learn about food-associated cues and the sensory properties of ingested foods. We found that rats fed a cafeteria diet for 2 weeks were impaired in the control of Pavlovian responding in accordance to the incentive value of palatable outcomes associated with auditory cues following devaluation by sensory-specific satiety. Sensory-specific satiety is one mechanism by which a diet containing different foods increases ingestion relative to one lacking variety. Hence, choosing to consume greater quantities of a range of foods may contribute to the current prevalence of obesity. We observed that rats fed a cafeteria diet for 2 weeks showed impaired sensory-specific satiety following consumption of a high calorie solution. The deficit in expression of sensory-specific satiety was also present 1 week following the withdrawal of cafeteria foods. Thus, exposure to obesogenic diets may impact upon neurocircuitry involved in motivated control of behavior.

Comment by Dr. Krishna Kumari Challa on September 3, 2014 at 7:30am

A better understanding of plasma cell signaling could lead to better vaccines and therapies for autoimmune disease.
Adaptor protein DOK3 promotes plasma cell differentiation by regulating the expression of programmed cell death 1 ligands
http://www.pnas.org/content/111/31/11431
Shp1 signalling is required to establish the long-lived bone marrow plasma cell pool
http://www.nature.com/ncomms/2014/140630/ncomms5273/full/ncomms5273...
Scientists have uncovered the crucial role of two signalling molecules involved in the development and production of plasma cells. These discoveries, published in the Proceedings of the National Academy of Sciences of the United States of America and Nature Communications, advance the understanding of plasma cells and antibody response, and may lead to optimised vaccine development and autoimmune disease treatments.

Comment by Dr. Krishna Kumari Challa on September 3, 2014 at 6:53am

Micromagnetic resonance relaxometry for rapid label-free malaria diagnosis
http://www.nature.com/nm/journal/vaop/ncurrent/full/nm.3622.html
A quick method detects by-products of the parasite's growth in the blood and is more portable and less error-prone than conventional tests
Jongyoon Han, a bioengineer at the Singapore-MIT Alliance for Research and Technology Centre, and his colleagues, have devised a diagnostic test that avoids many of the problems faced by today's anlysts. Their method, described in a paper published on 31 August in Nature Medicine, works with a tiny droplet — as little as 10 microlitres — of blood, and can provide a diagnosis in just a few minutes. In addition, it does not rely on the expertise of a technician.

When P. falciparum invades red blood cells and feeds on their contents, it breaks down haemoglobin into amino acids and haem, a chemical compound that contains iron. Free haem is toxic, so the parasite quickly converts it into an insoluble crystal known as haemozoin.

“Haemozoin crystals behave like little magnets,” explains Han. He and his team used a technique called magnetic resonance relaxometry (MRR) to detect the magnetic signal of haemozoin in human blood samples that they infected with P. falciparum, and in samples from mice infected withPlasmodium berghei, a mouse model of the disease.

MRR is a type of nuclear magnetic resonance (NMR) spectroscopy, a workhorse of chemical analysis. Although NMR machines are notoriously bulky, in recent years researchers have scaled them down to sizes small enough to fit on a benchtop. Another important step towards bringing the technique to the field, Han says, was that his team was able to detect haemozoin directly in the blood sample without first processing it in the lab.

• ‹ Previous
• 1
• …
• 951
• 952
• 953
• 954
• 955
• …
• 1079
• Next ›
• Page