Clipmarks | Mohir's 'dna' clips

Scientists Create World's Thinnest Balloon

Thu, 07 Aug 2008 21:28:33 GMT

clipped by: Mohir
clipper's remarks: Other potential applications include hyper-fine sensors and ultra-pure filters.

"Once you have a membrane that won't let anything past, the most interesting thing is to then poke a hole in it. Then you can detect what leaks through that hole with high sensitivity, or make sure only what you want leaks through that hole," McEuen said.

The only way gas leaked out from inside the balloons was through the glass that the bubbles were anchored on, McEuen explained.

Clip Source: www.livescience.com

Scientists have created the world's thinnest balloon, made of a single layer of carbon just one atom thick.

The fabric that the balloon is made of is leakproof to even the tiniest airborne molecules. It could find use in "aquariums" smaller than a red blood cell, through which scientists could peer at molecules, researchers suggested.

The balloon is made of graphite, as found in pencils, which is made of atom-thin sheets of carbon stacked on top of each other known. The sheets are known as graphene.

Graphene is highly electrically conductive, and scientists are feverishly researching whether it could find use in advanced circuitry and other devices.

In terms of applications,

"You could have instruments on one side of the membrane, in vacuum or air, and on the other side you would have DNA or proteins suspended in liquid," he explained. "And then you could get right up close to image the molecules, within a few angstroms," or widths of an atom.

Tags: technology

Were Ancient Viruses a Key to Human Evolution?

Fri, 01 Aug 2008 18:19:23 GMT

clipped by: Mohir
clipper's remarks: These viral fragments are fossils that reside within each of us, carrying a record that goes back millions of years. Because they no longer seem to serve a purpose or cause harm, these remnants have often been referred to as “junk DNA.” Although many of these evolutionary relics still manage to generate proteins, scientists have never found one that functions properly in humans or that could make us sick.
That is until Thierry Heidmann who runs the laboratory at the Institut Gustave Roussy, on the southern edge of Paris, brought one to life. Heidmann long suspected that if a retrovirus happens to infect a human sperm cell or egg, which is rare, and if that embryo survives—which is rarer still—the retrovirus could have the evolutionary power to influence humans as a species becoming part of the genetic blueprint, passed from mother to child, and from one generation to the next, much like a gene for eye color or asthma.

Clip Source: www.dailygalaxy.com

When the mapping of the human genome was completed in 2003, researchers discovered a shocking fact: our bodies are littered with the shards of retroviruses, fragments of the chemical code from which all genetic material is made. This discovery has created a new discipline, paleovirology, which seeks to better understand the impact of modern diseases by studying the genetic history of ancient viruses.

Highly infectious viral diseases -including the Plague, yellow fever, measles, smallpox and he Spanish Flu, which killed 50 million people at the end of the First World War, moving from one cell to the next, transforming each new host into a factory that makes even more virus. In this way, one infected cell soon becomes billion -that die when the host dies.

Endogenous retroviruses, however, once they infect the DNA of a species they become part of that species: they reside within each of us, carrying a record that goes back millions of years.

Tags: evolution, virus, dna

What Do Your Genes Say About You? The Future of Personal Genomics

Wed, 23 Jul 2008 21:21:02 GMT

clipped by: Mohir
clipper's remarks: The company 23andMe announced its DNA testing service last month in San Diego. You might think such a comprehensive analysis would costs thousands, but the process is actually relatively affordable. For less than $1,000 customers are able to learn virtually everything science currently knows about their biological code. For those wary of needles, you’ll be comforted to know that the DNA is retrieved conveniently and painlessly from a home mail-in saliva test kit.

Clip Source: www.dailygalaxy.com

Want to know what your genes say about you? According to geneticists, your genes could be saying quite a lot! Your genetics may dictate, for example, what foods you like, what diseases you are prone to develop, how smart you are, and likely factor into nearly every aspect of your being. It’s no wonder that some people would like to take a peek at their personal genetic blueprint.

Three companies are now offering such services. Not only will they test your DNA at nearly one million separate locations where the human genome is known to vary from person to person, but they also help clients interpret what their individual map says about their past, present and future. However, genetics is still an imperfect science. Your genes could indicate you have a very high risk of developing arthritis down the road, for example, but in actuality you may never suffer from stiff joints.

scientists have been mapping out genetic differences for some time now, and have made huge strides in interpreting DNA

Tags: dna, genetics

1998: Syphilis Genome Sequenced; 2008: Syphilis on the Rise

Sat, 19 Jul 2008 16:00:41 GMT

clipped by: Mohir
clipper's remarks: Incidence is up among women, African-Americans and, most prominently, gay men, who account for 64 percent of the more than 12,000 people diagnosed last year with either primary or secondary syphilis infections. Primary infections appear as ulcers or shankers on the genitals, anus or mouth; secondary infections result in rashes on the foot's sole or the palm of the hand as well as hair loss and lesions on or around the genitalia.

Clip Source: www.sciam.com

A decade ago, this week, scientists at the University of Texas Health Science Center at Houston and the Institute for Genomic Research announced they had decoded the genetic information inside Treponema pallidum, the bacterium that causes the sexually transmitted disease (STD) syphilis.

At the time, Penelope Hitchcock, the chief of the sexually transmitted disease branch of the National Institute of Allergy and Infectious Diseases (NIAID), hailed the work as critical to developing better drugs. NIAID director Anthony Fauci added the genome would boost efforts to develop a preventative vaccine.

Syphilis wouldn't have us to kick around anymore. Right?

Flash forward one decade: There are no new wonder drugs—penicillin injections are still the primary treatment and cure of the rarely fatal illness. Meanwhile, the rate of reported cases of syphilis in the U.S. rose for the seventh consecutive year—up 12 percent between 2006 and 2007

Tags: health, dna, syphilis

Dust Storms In Sahara Desert Sustain Life In Atlantic Ocean

Sat, 19 Jul 2008 15:02:07 GMT

clipped by: Mohir

Clip Source: www.sciencedaily.com

Research at the University of Liverpool has found how Saharan dust storms help sustain life over extensive regions of the North Atlantic Ocean.

Working aboard research vessels in the Atlantic, scientists mapped the distribution of nutrients including phosphorous and nitrogen and investigated how organisms such as phytoplankton are sustained in areas with low nutrient levels.

They found that plants are able to grow in these regions because they are able to take advantage of iron minerals in Saharan dust storms. This allows them to use organic or ‘recycled’ material from dead or decaying plants when nutrients such as phosphorous – an essential component of DNA – in the ocean are low.

“These findings are important because plant life cycles are essential in maintaining the balance of gases in our atmosphere. In looking at how plants survive in this area, we have shown how the Atlantic is able to draw down carbon dioxide from the atmosphere through the growth of photosynthesising plants.”

Tags: ecology, shara, life, atlantic

Four artificial new letters for the DNA alphabet

Mon, 14 Jul 2008 21:07:09 GMT

clipped by: Mohir

Clip Source: www.newscientist.com

A NEW type of artificial DNA may form the basis of minuscule electronic devices.

Natural DNA is constructed using four bases, which form the "letters" of the genetic code. Now Masahiko Inouye and his colleagues at the University of Toyama in Japan have used DNA synthesis equipment to stitch together four new artificial bases inside the sugar-based backbone of a DNA molecule (Journal of the American Chemical Society, DOI: 10.1021/ja801058h).

The artificial DNA is more stable than natural DNA, which may make it a good candidate for turning into molecular electronic wires, able to conduct electrons along their length.

So far the team has made only short strands of artificial DNA, around 100 bases long. But Inouye plans to experiment with naturally occurring enzymes, both to make longer strands of the molecule, and to make it copy itself, just like regular DNA.

Combining natural and unnatural bases could produce a whole range of interesting molecules

Tags: dna, electronics

Tiny fishing reel gets DNA researchers out of a tangle

Mon, 14 Jul 2008 19:48:53 GMT

clipped by: Mohir

Clip Source: technology.newscientist.com

The world's smallest fishing reel has been used to wind up DNA strands without damaging them. The microdevice was designed to let geneticists more precisely locate specific genes and identify genetic disorders.

Scientists use gene markers, which bind to specific DNA regions or chromosomes, to determine the presence of certain genetic disorders. But because DNA molecules tend to tangle, it can be difficult to see exactly where the markers have attached.

Now, Terao's team has developed minuscule hooks and bobbins that mimic the way a fishing reel winds line onto a spool as a safer way to manipulate DNA. These are fabricated from a polymer called SU-8 photoresist that doesn't bind to and damage the DNA.

Because the DNA isn't chemically modified before manipulation, and because the microhooks grab the middle of the molecules instead of the ends, breakages are less likely, says Terao.

Tags: dna, technology

Genes That Control Embryonic Stem Cell Fate Identified

Sun, 13 Jul 2008 18:28:33 GMT

clipped by: Mohir

Clip Source: www.sciencedaily.com

Scientists have identified about two dozen genes that control embryonic stem cell fate. The genes may either prod or restrain stem cells from drifting into a kind of limbo, they suspect. The limbo lies between the embryonic stage and fully differentiated, or specialized, cells, such as bone, muscle or fat.

By knowing the genes and proteins that control a cell's progress toward the differentiated form, researchers may be able to accelerate the process -- a potential boon for the use of stem cells in therapy or the study of some degenerative diseases, the scientists say.

"The genes we identified are necessary for embryonic stem cells to maintain a memory of who they are,"

"Without them the cell doesn't know whether it should remain a stem cell or differentiate into a specialized cell."

They found 22 proteins, each of which is essential for embryonic stem cells to maintain their consistent shape, growth properties, and pattern of gene expression.

Tags: stem cells, dna

Will "Th!nk" Ignite an Electronic Car Revolution in the U.S.?

Fri, 11 Jul 2008 17:55:18 GMT

clipped by: Mohir
clipper's remarks: Think City is one of two models that are out already, together with the Think Ox, with a choice of either lithium or a sodium battery, it's range is enough to take a suburban dweller to the downtown office and back, with zero carbon footprint. The car is thoughfully fully computerized and allows a key-less entry. It features real time navigation, web, e-mail and open source interfaces, intelligent and sustainable driving and route calculations. The DNA-key gives the user feedback on charging status and sends messages, for example, for pre-heat or pre-cool options via GPRS.
Pricing has yet to be announced, but the company's current vehicles cost less than $25,000.

Clip Source: www.dailygalaxy.com

Th!nk Global, yes, think with an exclamation mark, gas-free, city cars are poised to invade the U.S. from its Norwegian where some 1,200 Think concept vehicles are driving on European, mostly Norwegian, roads today. Th!nk is buoyed by undisclosed funding injection by Silicon Valley venture capital firms, Kleiner Perkins Caufield & Byers and RockPort Capital Partners, will be introducing the Ox, Open and City models starting in 2009 -and it can't be too soon!

With an an overnight power charge it’s ready to go in the morning -up to 200 kilometers (124 miles) in city driving on a fully charged battery, with a top speed of 100km/h. The lithium-ion batteries have capacity to charge to 80% capacity in less than an hour, and slender solar panels integrated into the roof power the dashboard electronics.

Tags: cars, green

First DNA molecule made almost entirely of artificial parts

Fri, 04 Jul 2008 18:49:02 GMT

clipped by: Mohir

Clip Source: www.kurzweilai.net

University of Toyama researchers have built the first DNA molecule made almost entirely of artificial parts.

The researchers used DNA synthesis equipment to assemble four artificial bases (basic building blocks of DNA) inside the framework of a DNA molecule. The unusually stable, double-stranded structures resemble natural DNA, which also has four bases.

Until now, scientists have only been able to craft DNA molecules with one or a few artificial parts, including certain bases.

The finding could lead to nanocomputers, improvements in gene therapy, and other high-tech advances.

Tags: dna

Electrostatic-based DNA Microarray Technique Could Revolutionize Medical Diagnostics

Mon, 30 Jun 2008 21:08:08 GMT

clipped by: Mohir
clipper's remarks: "One of the most amazing things about our electrostatic detection method is that it requires nothing more than the naked eye to read out results that currently require chemical labeling and confocal laser scanners," said Jay Groves, a chemist with joint appointments at Berkeley Lab's Physical Biosciences Division and the Chemistry Department of the University of California (UC) at Berkeley, who led this research. "We believe this technique could revolutionize the use of DNA microarrays for both research and diagnostics."

Clip Source: nextbigfuture.com

A team of researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) has invented a technique in which DNA or RNA assays — the key to genetic profiling and disease detection — can be read and evaluated without the need of elaborate chemical labeling or sophisticated instrumentation.

Based on electrostatic repulsion — in which objects with the same electrical charge repel one another — the technique is relatively simple and inexpensive to implement, and can be carried out in a matter of minutes.

Tags: dna, diagnostics

Five Reasons Why Aliens Will Make Contact with the Japanese First

Sun, 08 Jun 2008 17:10:18 GMT

clipped by: Mohir
clipper's remarks: North Korea is rumored to have recently released a statement claiming that their nuclear reactor has the dual capability of communicating wirelessly with alien species up to 1,000 light years away in real time. Of course, we can't believe everything that the North Korean government says, but seriously, I wouldn't be surprised at all if they were already communicating with other planets. If that's the case, it should be relatively easy for Japan, a neighboring country, to intercept their signals with laser pulses and let the world know definitively what Kim Jong Il has known for decades—that there is life beyond Earth.

Clip Source: io9.com

Here are five reasons why aliens might reach out to humankind via the islands of Japan first:

1. The Japanese are ready to greet them. Part of Defense Minister Shigeru Ishiba's national security strategy includes musings about how we'd respond to an alien attack under a pacifist constitution

2. We emailed them. In 1983, Japanese astronomers sent a radio message to Altair—a solar system 16 light years away—with 13 binary-encoded images 71 by 71 pixels each showing some basic facts about us, like where our planet is located, what humans look like, the structure of DNA, and the basic chemistry of life on earth. If someone on Altair had received this message, then we can expect a reply as early as 2015.

3. Japan has one of the only observatories that is actively seeking optical frequencies from outer space.

4. Japan will soon have AIs that match alien intelligence.

5. North Korea knows things the rest of us don't.

Tags: aliens, funny, japan

DNA Computer Puts Microbes to Work as Number Crunchers

Mon, 02 Jun 2008 18:24:50 GMT

clipped by: Mohir

Clip Source: www.sciam.com

Study shows genetic material in bacteria can be harnessed to solve complex math problems

It's not your normal, electronic silicon-based machine, but scientists have made a computer from a small, circular piece of DNA, then inserted it into a living bacterial cell and unleashed the microbe to solve a mathematical sorting problem.

"This work is the first work I've encountered which uses living cells in order to solve a specific computer science problem," says Tom Ran, a graduate student in the lab of computer scientist Ehud Shapiro at the Weizmann Institute in Rehovot, Israel.

"DNA computers may be able to accomplish things that electronic computers cannot," says Len Adleman, a molecular scientist at the University of Southern California. "For example, it is very hard to conceive putting an electronic, silicon-based computer into a bacterial cell."

Tags: dna, computers, bacteria

Gut bugs may have guided the evolution of life

Tue, 27 May 2008 12:05:42 GMT

clipped by: Mohir
clipper's remarks: They found more than 20,000 different kinds of bacteria. But the closer two species were on the tree of life, the more bacterial species they had in common living in their guts.

Clip Source: www.newscientist.com

The history of evolution could be written in an animal's excrement. A new analysis of faeces from dozens of mammals, including humans, suggests that gut-dwelling microbes might shape animal evolution.

Trillions of mostly harmless bacteria and other microbes inhabit the guts of all mammals, outnumbering the number of mammalian cells by 10 to one.

Now, a census of the microbes living in 60 mammals, from cows to kangaroos to capybaras, has found that closely related animals and those with similar diets tend to have the same species of gut microbes.

Scientists have long known that our stomachs team up with harmless bugs, but we are only beginning to appreciate the breadth of bacterial diversity in our bellies. By reading the chemical letters of a molecule called 16s ribosomal RNA – a cousin to DNA – researchers can catalogue bacterial species and conduct a rough census of their numbers.

Tags: evolution

Huge hidden biomass lives deep beneath the oceans

Sun, 25 May 2008 18:02:34 GMT

clipped by: Mohir
clipper's remarks: They found simple organisms known as prokaryotes in every sample. Prokaryotes are organisms that often have just one cell. Their peculiarity is that, unlike any other form of life, their DNA is not neatly packed into a nucleus.

Clip Source: environment.newscientist.com

It's the basement apartment like no other. Life has been found 1.6 kilometres beneath the sea floor, at temperatures reaching 100 °C.

The discovery marks the deepest living cells ever to be found beneath the sea floor. Bacteria have been found deeper underneath the continents, but there they are rare. In comparison, the rocks beneath the sea appear to be teeming with life.

John Parkes, a geobiologist at the University of Cardiff, UK, hopes his team's discovery might one day help find life on other planets. He says it might even redefine what we understand as life, and, bizarrely, what we understand by "age".

Parkes has been hunting for deep life for over 20 years. Recently, he and his colleagues examined samples of a mud core extracted from between 860 metres and 1626 metres beneath the sea floor off the coast of Newfoundland.

Tags: life, sea, ocean