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Comment by Dr. Krishna Kumari Challa on March 19, 2015 at 8:33am

Language of gene switches unchanged across the evolution
The language used in the switches that turn genes on and off has remained the same across millions of years of evolution, according to a new study led by researchers at Karolinska Institutet in Sweden. The findings, which are published in the scientific journal eLife , indicate that the differences between animals reside in the content and length of the instructions that are written using this conserved language.
Each gene has a regulatory region that contains the instructions controlling when and where the gene is expressed. These instructions are written in a language often referred to as the 'gene regulatory code'. This code is read by proteins called transcription factors that bind to specific ‘DNA words’ and either increase or decrease the expression of the associated gene.

The gene regulatory regions differ between species. However, until now, it has been unclear if the instructions in these regions are written using the same gene regulatory code, or whether transcription factors found in different animals recognise different DNA words.

In the current study, the researchers used high throughput methods to identify the DNA words recognised by more than 240 transcription factors of the fruit fly, and then developed computational tools to compare them with the DNA words of humans.
Tiny fruit flies look very different from humans, but both are descended from a common ancestor that existed over 600 million years ago. Differences between animal species are often caused by the same or similar genes being switched on and off at various times and in different tissues in each species.
In the new study, it has been observed that, in spite of more than 600 million years of evolution, almost all known DNA words found in humans and mice were recognised by fruit fly transcription factors.
The researchers also noted that both fruit flies and humans have a few transcription factors that recognise unique DNA words and confer properties that are specific to each species, such as the fruit fly wing. Likewise, transcription factors that exist only in humans operate in cell types that do not exist in fruit flies. The findings suggest that changes in transcription factor specificities contribute to the formation of new types of cells.

The study of fundamental properties of gene switches is important in medicine, as faulty gene switches have been linked to many common diseases, including cancer, diabetes and heart disease.

http://elifesciences.org/content/4/e04837

Comment by Dr. Krishna Kumari Challa on March 19, 2015 at 7:36am

Long-term decline of the Amazon carbon sink
Amazon rainforest losing capacity to soak up CO2
The Amazon rainforest may be approaching the limit of how much excess carbon dioxide it can capture from the atmosphere.

A global research effort, led by scientists from the University of Leeds, has revealed a one-third decline in the rainforest' growth overall, according to a paper published today in Nature.

This could have significant implications for global carbon dioxide levels, as the rainforest previously absorbed up to two billion tonnes of carbon dioxide each year, converting it into biomass.

http://www.nature.com/nature/journal/v519/n7543/full/nature14283.html

Comment by Dr. Krishna Kumari Challa on March 19, 2015 at 6:42am

Comment by Dr. Krishna Kumari Challa on March 19, 2015 at 6:17am

Look, your eyes are wired backwards: here’s why
The human eye is optimised to have good colour vision at day and high sensitivity at night. But until recently it seemed as if the cells in the retina were wired the wrong way round, with light travelling through a mass of neurons before it reaches the light-detecting rod and cone cells. New research presented at a meeting of the American Physical Society has uncovered a remarkable vision-enhancing function for this puzzling structure.
Researchers in Leipzig found that glial cells, which also span the retinal depth and connect to the cones, have an interesting attribute. These cells are essential for metabolism, but they are also denser than other cells in the retina. In the transparent retina, this higher density (and corresponding refractive index) means that glial cells can guide light, just like fibre-optic cables.
These results mean that the retina of the eye has been optimised so that the sizes and densities of glial cells match the colours to which the eye is sensitive (which is in itself an optimisation process suited to our needs). This optimisation is such that colour vision during the day is enhanced, while night-time vision suffers very little. The effect also works best when the pupils are contracted at high illumination, further adding to the clarity of our colour vision.
https://theconversation.com/look-your-eyes-are-wired-backwards-here...

Comment by Dr. Krishna Kumari Challa on March 19, 2015 at 6:06am

The latest Research advance published by eLife is a study by Syenina et al. The authors have discovered that, when a person is infected by the dengue virus for a second time, antibodies specific to the dengue virus interact with mast cells lining our blood vessels and enhance vascular leakage. The study builds upon earlier research looking into why a small percentage of infected individuals go on to suffer from dengue hemorrhagic fever. They find that the vascular leakage triggered by this hemorrhagic fever is triggered by mast cells indicating a potential new treatment target.
http://elifesciences.org/content/4/e05291#sthash.LI0mDyAD.dpuf?utm_...

Comment by Dr. Krishna Kumari Challa on March 18, 2015 at 8:50am

Darbha (Desmotachya bipinnata) is a tropical grass considered a sacred material in Vedic scriptures and is said to purify the offerings during such rituals.

At the time of eclipse, people place that grass in food items that could ferment and once the eclipse ends the grass is removed.

A systematic research was conducted by the SASTRA University researchers, in which cow’s curd was chosen as a food item that could ferment easily.

Five other tropical grass species, including lemon grass, Bermuda grass, and bamboo were chosen for comparison based on different levels of antibiotic properties and hydro phobicity.

Electron microscopy of different grasses revealed stunning nano-patterns and hierarchical nano or micro structures in darbha grass while they were absent in other grasses.

On studying the effect of various grasses on the microbial community of the curd, darbha grass alone was found to attract enormous number of bacteria into the hierarchical surface features.

These are the bacteria responsible for fermentation of cow’s curd.

During eclipse, the wavelength and intensity of light radiations available on the earth’s surface is altered. Especially, the blue and ultraviolet radiations, which are known for their natural disinfecting property, are not available in sufficient quantities during eclipse.

This leads to uncontrolled growth of micro-organisms in food products during eclipse and the food products are not suitable for consumption. Darbha was thus used as a natural disinfectant on specific occasions, say researchers at SASTRA University.

Further, the scientists say that darbha could be used as a natural food preservative in place of harmful chemical preservatives and the artificial surfaces mimicking the hierarchical nano patterns on the surface of darbha grass could find applications in health care where sterile conditions were required.

Comment by Dr. Krishna Kumari Challa on March 17, 2015 at 9:02am

Folic acid supplementation cuts risk of stroke in hypertensive adults
Use of folic acid therapy results in significant reduction of risk of stroke among adults with hypertension (high blood pressure). This is the main finding of a new study published in the Journal of the American Medical Association (JAMA). The study from the China Stroke Primary Prevention Trial (CSPPT), included data on 20,702 adults in China and has been published to coincide with its presentation at the American College of Cardiology Annual Scientific Session.
The results of the study showed that for the primary outcome, which was first stroke, the folic acid plus enalapril supplement resulted in significant reduction in risk compared to enalapril alone (2.7% of participants in the enalapril–folic acid group vs 3.4% in the enalapril alone group). Relative risk of first ischemic stroke (2.2% with enalapril–folic acid vs 2.8% with enalapril alone) and composite cardiovascular events consisting of cardiovascular death, mycocardial infarction and stroke (3.1% with enalapril–folic acid vs 3.9% with enalapril alone) was also significantly reduced. The beneficial effect of folic acid supplementation was most pronounced in participants with lower baseline folate levels. With respect to the MTHFR genotype and baseline folate level, among individuals with CC or CT genotypes, both highest risk of stroke and greatest benefit of folic acid therapy were in participants with the lowest baseline folate levels. For those with the TT genotype, the results indicated that the biological level of folate insufficiency may necessitate higher dosage of folic acid supplementation.
Efficacy of Folic Acid Therapy in Primary Prevention of Stroke Among Adults With Hypertension in China
http://jama.jamanetwork.com/article.aspx?articleid=2205876

Comment by Dr. Krishna Kumari Challa on March 17, 2015 at 8:34am

Humans may harbor more than 100 genes from other organisms
You’re not completely human, at least when it comes to the genetic material inside your cells. You—and everyone else—may harbor as many as 145 genes that have jumped from bacteria, other single-celled organisms, and viruses and made themselves at home in the human genome. That’s the conclusion of a new study, which provides some of the broadest evidence yet that, throughout evolutionary history, genes from other branches of life have become part of animal cells.
Scientists knew that horizontal gene transfer—the movement of genetic information between organisms other than parent-to-offspring inheritance—is commonplace in bacteria and simple eukaryotes. The process lets the organisms quickly share an antibiotic-resistance set of genes to adapt to an antibiotic, for instance. But whether genes have been horizontally transferred into higher organisms—like primates—has been disputed. Like in bacteria, it’s been proposed that animal cells could integrate foreign genetic material that’s introduced as small fragments of DNA or carried into cells by viruses. But proving that a bit of DNA in the human genome originally came from another organism is tricky.
A group of researchers now pinpointed hundreds of genes that appeared to have been transferred from bacteria, archaea, fungi, other microorganisms, and plants to animals, they report online today in Genome Biology. In the case of humans, they found 145 genes that seemed to have jumped from simpler organisms, including 17 that had been reported in the past as possible horizontal gene transfers.
http://news.sciencemag.org/biology/2015/03/humans-may-harbor-more-1...

http://genomebiology.com/2015/16/1/50

Expression of multiple horizontally acquired genes is a hallmark of both vertebrate and invertebrate genomes

Comment by Dr. Krishna Kumari Challa on March 17, 2015 at 8:28am

Origins of life: A new study has shown you can create the most simple building blocks of life using three things that would have been present in abundance on early Earth - hydrogen cyanide (HCN), hydrogen sulphide (H2S), and ultraviolet (UV) light.
In order for life to have gotten started, there must have been a genetic molecule - something like DNA or RNA - capable of passing along blueprints for making proteins, the workhorse molecules of life. But modern cells can’t copy DNA and RNA without the help of proteins themselves.

To make matters more vexing, none of these molecules can do their jobs without fatty lipids, which provide the membranes that cells need to hold their contents inside. And in yet another chicken-and-egg complication, protein-based enzymes (encoded by genetic molecules) are needed to synthesise lipids.
A team led by chemist John Sutherland from the University of Cambridge in the UK has made a discovery that just might resolve this problem. Six years ago, they figured out that simple and very common carbon-rich molecules, acetylene and formaldehyde, can be put through a series of reactions to produce some of the precursors for RNA. So perhaps billions of reactions between acetylene and formaldehyde over billions of years could have randomly given rise to the first RNA molecules. But, says Service, this doesn’t answer the question of where the acetylene and formaldehyde came from.
Sutherland and his team investigated, and came up with even simpler ingredients for RNA, and these ones we know were abundant when Earth was only newly formed - hydrogen cyanide, hydrogen sulphide, and ultraviolet light. Together, these three ingredients can not only produce ribonucleotides, which are the basic building blocks for RNA, but more importantly, they can also produce amino acids and lipids at the same time, which helps solve the conundrum outlined by Service above. The lipids are there to provide the materials for the cell membranes, and the amino acids are needed to form the proteins that help replace and pass on DNA and RNA. So where did these chemicals come from? Meteorites could have converted hydrogen cyanide from some of the simplest molecules you can get - carbon, hydrogen, and nitrogen - right near early Earth. "Evidence suggests that life started during, or shortly after the abatement of, the Late Heavy Bombardment, and processes associated with meteorite impact have been implicated in the generation of hydrogen cyanide and phosphate on the Hadean [early] Earth,” the team writes.

And hydrogen sulphide and ultraviolet light were already in the area, so it wouldn’t have taken much for the various molecules to eventually make contact with each other.
http://www.nature.com/nchem/journal/vaop/ncurrent/full/nchem.2202.html

Comment by Dr. Krishna Kumari Challa on March 17, 2015 at 8:22am

BIOENGINEERING
A synthetic fibrin cross-linking polymer for modulating clot properties and inducing hemostasis

New gel can stop wounds from bleeding

And could find applications on the battlefield, or in the toolkits of emergency response teams.
Traumatic injuries resulting from gunshot wounds or traffic accidents, can often be fatal if the injured person doesn’t receive prompt medical care.

Now, an injectable polymer material that encourages faster, more durable blood clotting at wound sites, could stop bleeding following these life-threatening injuries.
The material, known as PolySTAT, was developed by engineers at the University of Washington in the US, and mimics a natural protein in our body that helps strengthen blood clots.

The team says that following injection, their wound healing polymer “circulates innocuously in the blood, identifies sites of vascular injury, and promotes clot formation to stop bleeding”.

So far they have only tested their polymer on rats, but report in the press release that 100 percent of the animals injected survived “a typically-lethal injury to the femoral artery”.
The results have been published in the journal Science Translational Medicine
http://stm.sciencemag.org/content/7/277/277ra29

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