Science Simplified!

Comment

Comment by Dr. Krishna Kumari Challa on November 22, 2014 at 7:04am

Shaping the oral microbiota through intimate kissing
http://www.microbiomejournal.com/content/2/1/41
. A single 10-second smooch can transfer tens of millions of bacteria from one partner to the other. That’s the finding from a study.
More than 700 different bacteria are estimated to live in the human mouth. To find out how macking mixes microbes, Dutch scientists asked 21 couples to French kiss.
Similarity indices of microbial communities show that average partners have a more similar oral microbiota composition compared to unrelated individuals, with by far most pronounced similarity for communities associated with the tongue surface. An intimate kiss did not lead to a significant additional increase of the average similarity of the oral microbiota between partners. However, clear correlations were observed between the similarity indices of the salivary microbiota of couples and self-reported kiss frequencies, and the reported time passed after the latest kiss. In control experiments for bacterial transfer, we identified the probiotic Lactobacillus and Bifidobacterium marker bacteria in most kiss receivers, corresponding to an average total bacterial transfer of 80 million bacteria per intimate kiss of 10 s.

This study indicates that a shared salivary microbiota requires a frequent and recent bacterial exchange and is therefore most pronounced in couples with relatively high intimate kiss frequencies. The microbiota on the dorsal surface of the tongue is more similar among partners than unrelated individuals, but its similarity does not clearly correlate to kissing behavior, suggesting an important role for specific selection mechanisms resulting from a shared lifestyle, environment, or genetic factors from the host. Furthermore, our findings imply that some of the collective bacteria among partners are only transiently present, while others have found a true niche on the tongue’s surface allowing long-term colonization.

Comment by Dr. Krishna Kumari Challa on November 21, 2014 at 8:44am

Two new subatomic particles whose existence was predicted by Canadian particle physicists have been detected at the world's largest particle collider.

The discovery of the particles, known as Xi_b'- and Xi_b*-, were announced by CERN, the European Organization for Nuclear Research today and published online on the physics preprint server Arxiv.They have been submitted to the scientific journal Physical Review Letters.
The new particles are baryons – a type of particle each made up of three elemental subatomic particles called quarks. The protons and neutrons that make up atoms are also baryons, but the new particles are about six times more massive than a proton.

That's because they contain a very heavy kind of quark called a b quark – also known as a beauty or bottom quark. The two other quarks in the particles are the d or down quark – a very light type of quark that is also found in protons and neutrons – and a middleweight strange quark.

Comment by Dr. Krishna Kumari Challa on November 21, 2014 at 8:38am

Were Neanderthals a Separate Species? Scientists Say Yes, By a Nose

Our genes suggest that modern humans interbred with Neanderthals, and that's led some anthropologists to claim Homo neanderthalensis should be considered a subspecies of Homo sapiens rather than a separate species. But other researchers disagree, and one team of specialists says the Neanderthals' nasal anatomy proves they were a species of their own. The comparisons of 3-D coordinates from CT scans of ancient fossils are published in the November issue of The Anatomical Record. "By looking at the complete morphological pattern, we can conclude that Neanderthals are our close relatives, but they are not us," Jeffrey Laitman, an anatomist at the Icahn School of Medicine at Mount Sinai, said in a news release.

Comment by Dr. Krishna Kumari Challa on November 21, 2014 at 6:59am

Comment by Dr. Krishna Kumari Challa on November 21, 2014 at 6:57am

Comment by Dr. Krishna Kumari Challa on November 21, 2014 at 6:14am

Science and magic:

The magician deals out six cards and asks the spectator to reveal only the color of each card. The spectator then chooses one of them and the Phoney app miraculously predicts his or her card.

A lot of science in this illusion. Part of it was a matter of probability. “Think of it as a sequence of six, where each card can be a 1 or a 0, black or red,” Williams says. “That’s 26, or 64 different combinations. There are only 52 cards in a deck, so we have enough information.”

There was also a cognitive element. people studied card preferences, and found that subjects had a strong inclination toward high-ranking cards, red cards and hearts. They programmed this app to recognize these preferences when predicting which card the spectator had chosen.

During the actual performance, several illusions happen at once. First, a fresh deck of cards is cut but never actually shuffled. Then, as the spectator calls out each card’s color, the magician uses a fake lock screen—Watch the video again, carefully!—to enter that information into the system. Finally, the app combines preprogrammed preferences with probability calculations to choose the most likely card. Magicians have a lot of experience, and a lot of that depends on the human component—[they] use the fact that human beings are what they are. Of course, that’s all based on mathematical principles.

Comment by Dr. Krishna Kumari Challa on November 19, 2014 at 8:52am

Antiviral microbicides effective against HIV in lab tests have had inconsistent results in people. A new study that includes semen and vaginal fluids, often missing elements in laboratory studies, finds that semen actually inhibits microbicides from killing HIV.

But the study, published in the November 12 Science Translational Medicine, also finds that semen didn’t diminish the antiviral effect of one microbicidal drug called maraviroc, which works differently from others. While most microbicides target components of HIV itself, maraviroc targets the receptor protein that serves as the entry point on cells that HIV is seeking to invade.

Maraviroc stopped infection when tested in cervical cells exposed to semen-treated HIV, suggesting that agents targeting these protein receptors on cells might be more promising than those aimed at the virus itself.
https://www.sciencenews.org/blog/science-ticker/semen-seems-counter...

Comment by Dr. Krishna Kumari Challa on November 19, 2014 at 8:44am

– Moldy houses are hard on the lungs, and new results in mice suggest that they could also be bad for the brain. Inhaling mold spores made mice anxious and forgetful, researchers reported November 15 at the annual meeting of the Society for Neuroscience.

Cheryl Harding, a psychologist at the City University of New York, and colleagues dripped low doses of spores from the toxic mold Stachybotrys into mouse noses three times per week. After three weeks, the mice didn’t look sick. But they had trouble remembering a fearful place. The mice were also more anxious than normal counterparts. The anxiety and memory deficits went along with decreases in new brain cells in the hippocampus — a part of the brain that plays a role in memory — compared with control mice.

Harding and colleagues also found that the behaviors linked to increased inflammatory proteins in the hippocampus. Exposure to mold’s toxins and structural proteins may trigger an immune response in the brain. The findings, Harding says, may help explain some of the conditions that people living in moldy buildings complain about, such as anxiety and cognitive problems.
https://www.sciencenews.org/article/mold-may-mean-bad-news-brain

Comment by Dr. Krishna Kumari Challa on November 19, 2014 at 7:18am

Scientists Sequence Genomes of 17 World’s Oldest Living People to see if they could uncover the genetic basis for extreme human longevity.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone....
Supercentenarians are the world’s oldest people, living beyond 110 years of age. 74 are alive worldwide, with 22 living in the United States.

Dr Kim and his colleagues from Stanford University, the Institute for Systems Biology in Seattle, and the University of California Los Angeles, performed whole-genome sequencing on 17 supercentenarians to explore the genetic basis underlying their extreme longevity.
One possibility is that a specific mutation could alter the protein-coding region in a gene and confer a significant increase in longevity. Such a mutation could act in a dominant or recessive fashion, and might be shared by a significant fraction of the supercentenarian genomes.”

“Another possibility is that there may be a gene that confers extreme longevity when it is altered by any one of a number of protein alterations.”

“Many of the supercentenarians may carry variants in the same gene, but the variant in each supercentenarian may be different. The variants could act in a dominant fashion and affect only one of the two alleles. Or else they could act in a recessive fashion such that both alleles would be affected, either with the same variant or with different mutations in each allele.”

The scientists analyzed rare protein-altering variants, but found no significant evidence of enrichment for a single rare protein-altering variant or for a gene harboring different rare protein altering variants in the supercentenarians compared to control genomes (379 European individuals from the 1000Genomes Project).

Comment by Dr. Krishna Kumari Challa on November 19, 2014 at 7:01am

Adaptive evolution: Can we read the future from a tree?
A new method uses genealogies based on sequence data to predict short-term evolutionary patterns.
http://elifesciences.org/content/3/e05060

Evolutionary biology is gaining predictive power in an increasing number of systems, which include viruses, bacteria and populations of cancer cells. In these systems, high mutation rates make evolution happen in front of our eyes. Every year, for example, the human influenza virus replaces 2% of the amino acids in the protein domains that interact with the immune system of its host. Using modern genome sequencing, we can now monitor the genetic history of entire populations and reconstruct their genealogical trees. Such trees show how the individuals of today's populations are connected to their evolutionary ancestors.

• ‹ Previous
• 1
• …
• 902
• 903
• 904
• 905
• 906
• …
• 1043
• Next ›
• Page