KANSAS CITY, Mo. A Missouri man forced to provide a DNA sample after pleading guilty in a drunken driving case has been charged in a 23-year-old killing.

Prosecutors announced Friday that Guy Shannon Jr., 43, of Odessa, faces charges of first-degree murder and forcible rape. Shannon is accused of strangling and assaulting Marcia Lynn Davis, 20, of Independence, in March 1989.

Davis was last seen leaving the Jackson County Jail after visiting a friend. A homeless person found her partially clad body in an abandoned apartment building the next day, according to a probable cause statement filed in the case.

Shannon became a suspect after he was convicted of driving while intoxicated in 2010 and, as a felon, had to give a DNA sample. It was entered in a database and ultimately linked him to genetic material found on Davis' body. Authorities said only one in 10 quadrillion unrelated people would have the same genetic profile.

Davis' friends and family were shown Shannon's photo but didn't recognize him, the probable cause statement said.

When interviewed, Shannon said he had never seen Davis before. He told authorities he had never been to the building where her body was found or picked up hitchhikers or women on the street.

Shannon requested an attorney when told his DNA was found on the victim, the probable cause statement said.

Although the charges were filed Monday, the case was temporarily sealed until Thursday, when the warrant was served.

Bond has been set at $350,000. No attorney is listed for Shannon in online court records.

In the early 1970s, Kansas City police started more carefully archiving physical evidence from hundreds of unsolved homicides, rapes and other crimes, often storing it in a giant freezer in the city's crime lab. Ensuing technological advances made the practice pay off, with numerous cold cases solved with the old physical evidence.

Continued here:
DNA from DWI links man to cold-case murder

RICHMOND, Va. --

Prompted by DNA testing in recent years, authorities in Norfolk and Carroll County are investigating several possible wrongful convictions from decades ago.

The Virginia Department of Forensic Science has disclosed DNA test results for more than 70 people in which testing of biological evidence discovered in forensic case files from 1973 to 1988 failed to identify the convicted person.

The test reports were released in response to Freedom of Information Act requests from the news media and the Innocence Project made possible as of July 1 by special legislation passed by the General Assembly this year.

Failure to identify a convicted person's DNA in evidence, primarily blood and semen, can be consistent with and even prove innocence, or it may mean nothing.

As permitted by the legislation, two commonwealth's attorneys are withholding four DNA reports involving five people four in Norfolk and one in Carroll County deemed critical to ongoing criminal investigations, the department said.

But Amanda M. Howie, a spokeswoman for Norfolk Commonwealth's Attorney Gregory D. Underwood, said that of 11 DNA reports sent to Norfolk for consideration, they objected to the release of four concerning three individuals and two cases.

"Our objection is appropriate as our legal review of the original circumstances of each case associated with the (reports) is still ongoing," Howie wrote in an email.

She said that in every case sent to her office, "a thorough, routine process is followed to determine what, if any, legal impact the testing and resulting (report) has on the case."

The Commonwealth's Attorney's Office in Carroll did not return calls for comment Friday. Other investigations in the roughly three dozen jurisdictions with exclusion cases may be in progress as well.

Originally posted here:
DNA tests prompt investigations of possible wrongful convictions

Credit: BOB BROWN/RICHMOND TIMES-DISPATCH

Thomas E. Haynesworth at a December 2011 press conference with Attorney General Ken Cuccinelli and Shawn Armbrust of the Mid Atlantic Innocence Project.

Prompted by DNA testing in recent years, authorities in Norfolk and Carroll County are investigating several possible, decades-old wrongful convictions.

Virginia Department of Forensic Science has disclosed DNA test results for more than 70 persons where testing of biological evidence discovered in forensic case files from 1973 to 1988, failed to identify the convicted person.

The test reports were released in response to Freedom of Information Act requests from the media and the Innocence Project made possible -- as of July 1 -- by special legislation passed by the Virginia General Assembly this year.

Failure to identify a convicted persons DNA in evidence, primarily blood and semen, can be consistent with and even prove innocence but may mean nothing.

However, as permitted by the legislation, the department said two Commonwealths attorneys are withholding four reports involving five people four in Norfolk and one in Carroll County -- deemed critical to ongoing criminal investigations.

Amanda M. Howie, a spokeswoman for Gregory D. Underwood, the Norfolk Commonwealths attorney, said that of 11 reports sent to Norfolk for consideration, they objected to the release of four concerning 3 individuals and 2 cases.

Howie wrote in an email that, Our objection is appropriate as our legal review of the original circumstances of each case associated with the (reports) is still ongoing.

She said that in every case sent to her office, a thorough, routine process is followed to determine what, if any, legal impact the testing and resulting (report) has on the case.

Read this article:
DNA tests prompt review of 5 possible wrongful convictions

(Phys.org) -- Our electronic devices are getting smaller and smaller while doing more and more. Using conventional materials, we will soon reach the practical limit. The electronics of tomorrow require alternatives, such as nanowires made of DNA that can serve as conductive paths and nanotransistors for miniature circuits. In the journal Angewandte Chemie, German scientists have now described a new method for the production of stable, conducting DNA nanowires.

DNA is more than a carrier of genetic information; it is also an interesting building material for nanotechnology. This is because of its extraordinary self-organizational properties. DNA is thus often used as a mold for the production of nanoscale structures. Its use in the assembly of electronic circuits is hampered by the fact that DNA is a very poor conductor of electricity. One way to get around this is by depositing metal onto the DNA strands.

Scientists at the RWTH Aachen and the University of Munich have now developed a new strategy for the controlled production and metallization of DNA nanostructures. Led by Ulrich Simon, the team used a DNA strand consisting of an immobilization sequence and a metallization sequence. Several such strands are strung together so that the resulting DNA is made of alternating sequences.

The immobilization sequence contains alkyne groups. These allow the DNA to be snapped into place on a silicon wafer coated with azide groups in what is known as a click reaction. The other DNA segment has two tasks: it is equipped with functional groups that cause the aggregation of silver particles and can also attach DNA strands to each other.

The DNA strands are stretched, deposited onto the wafers, and attached by the click reaction. During the subsequent metallization with silver particles, neighboring strands are simultaneously cross-linked to form multistrands. These have significantly higher structural stability than single strands. In the future, this method could also be used to integrate the DNA strands into programmable DNA architectures to allow for the positioning and binding of complex structures on prestructured substrates.

Deposition of the silver particles does not complete the metallization process. In a second step, which resembles the development of photographs, gold from a solution can be deposited onto the silver particles. Changing the duration of the gold deposition process allows for variation of the diameter of the resulting nanowires.

This new method allowed the scientists to obtain micrometer-long, electrically contactable nanowires that have potential for development into further miniaturized circuits.

More information: Ulrich Simon, Surface "Click" Reaction of DNA followed by Directed Metalization for the Construction of Contactable Conducting Nanostructures, Angewandte Chemie International Edition, dx.doi.org/10.1002 ie.201202401

Journal reference: Angewandte Chemie Angewandte Chemie International Edition

Provided by Wiley

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DNA as future electronic components: Conducting nanostructures based on metallized DNA

How long will it be before prenatal care involves sequencing the genome of a fetus to detect genetic disorders before birth? Several recent reports have shown it can be done, based on the tiny bits of DNA that float around in the mother-to-bes blood plasma during pregnancy.

Another such study came out this week in the journal Nature -- with some important advances.

In the past, fetal-genome analyses have involved getting samples of DNA from three places: the womans blood cells (to identify her genome), the womans blood plasma (to detect fetal DNA in addition to her own) and cells from the father-to-be's saliva (to know for sure what bits of his DNA the fetus inherited).

But sampling the mans DNA is a particularly delicate issue, the study authors note, since the incidence of non-paternity is estimated to be between 3% and 10%.

In the new study, senior author Stephen R. Quake and colleagues at Stanford University did the entire analysis without sampling the mans DNA.

As reported before, the authors were able to infer which bits of the womans genome had been picked up by the fetus since those DNA regions were present in the plasma in extra amounts. But they could also accurately deduce the father-to-bes genome by identifying bits of genome that did not come from the woman.

Paternity issues aside, the authors note that there are substantial ethical issues associated with noninvasive prenatal genetic determination, which we have not attempted to address. We will note however that there are numerous clinical scenarios where this approach would be useful.

If the test is done early -- in the first or second trimester -- it could detect genetic conditions that are not survivable or will cause medical complications, they write. With medical advances, it might be possible to treat or even cure these conditions while the baby is still growing inside the woman.

Tests done in the third trimester could help reveal before birth if a fetus has inherited a serious disorder that can respond well to timely treatment. That could prevent harm or suffering, the authors say. Diseases they mention include phenylketonurea and maple syrup urine disease. In both cases, the disorder affects metabolism of certain amino acids and a special diet is needed to avoid harm to brain and body.

One of the pregnant women in the study was carrying a fetus with a genetic disorder known as DiGeorge syndrome. Caused by a deletion on Chromosome 22, the syndrome is characterized by an array of medical problems including heart defects, cleft palate and low blood calcium. In this clinical scenario, confirmation of the deletion would argue for a fetal echocardiogram and neonatal assessment of calcium levels, the authors write.

See the article here:
Entire genome of fetus sequenced without DNA from man

A new DNA test offered at Thomas Memorial Hospital is helping psychiatrists more quickly determine which drugs work best for their patients.

Thomas Memorial started offering the DNA tests in January at its South Charleston imaging center.

"You walk to the laboratory, the representative takes a giant cotton swab, swabs the inside of your cheek and you leave. It could not be much more simple," Dr. Tara F. Ray said.

The hospital then ships the swabs to a company called AssureRX, where lab technicians run DNA tests on the samples.

"Based on certain kinetic DNA types, you can determine what medication a patient may not tolerate well or what drug might work well," Ray said.

In a few days, doctors get the test results back with medication suggestions. Ray said the information is separated into three columns: medications that should work, medications that might work but should be monitored closely and medications that patients should avoid.

"It really helps narrow the focus of where to start," she said.

Doctors receive several bits of information from the DNA results, including how fast their patients' bodies break down certain enzymes. People with quick metabolisms need a higher dosage, because their bodies break down medications faster.

A person with a slower metabolism, however, needs a lower dosage because their body doesn't break down drugs as quickly. That leads to higher concentrations of medication in their bloodstream, creating greater potential for side effects.

Ray said the medication list is limited at this time, but AssureRX is always adding more to the list. She said even with the short list, the DNA testing has helped limit the amount of experimentation she has to do when prescribing new drugs.

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DNA test helps hospital choose right medication

LIVINGSTON - Henry Skinner is a small man with a crooked nose, acid tongue and keen mind. Convicted of fatally pummeling his lover with an ax handle and stabbing her adult sons in a 1993 New Year's Eve Texas Panhandle rampage, he has used his 17 years on death row to assail Texas' criminal justice system as "cunning and deceptive."

In a case that has become an international anti-death penalty cause clbre, Skinner since 2001 has battled to obtain DNA testing of items he believes will clear him of the Pampa killings of Twila Busby and her sons, Randy and Elwin.

Skinner's campaign for more testing twice has prompted courts to stay his scheduled executions. His quest has been complicated by his first lawyer's decision to abandon DNA testing after examination of clothing worn by Skinner on the night of the killings revealed traces of the victims' blood.

Despite prosecutor-sanctioned testing of a few items in 2000 and a 2011 U.S. Supreme Court ruling that opened a new avenue to such testing, rape kit specimens, knives, fingernail scrapings and an apparently bloodstained windbreaker found near Busby's body still have not been examined.

All that changed last month when the Texas Attorney General's Office dropped its opposition to testing and, in tandem with Skinner's lawyers, compiled a list of more than 40 items for high-tech examination.

The items are to be turned over to Texas Department of Public Safety lab technicians on Thursday.

"This nightmare is almost over," Skinner said in a recent death-row interview. "I'm looking forward to the day I can leave. I'll either leave with a few boxes under my arm or in a box. I've already spent 18 years in hell."

Key evidence lost

The state's seeming capitulation appeared a breakthrough for Skinner, who has orchestrated a "Free Skinner" campaign through frequent prison cell pronouncements and postings on his website, "Hell Hole News."

Even as Skinner's lawyers and supporters breathed a sigh of relief, though, it once again appeared the victory may only be partial. State lawyers admit that, after a thorough search, they cannot find the windbreaker, which Skinner attorney Rob Owen called a key piece of evidence.

See the article here:
State to get Skinner evidence for DNA testing

Scientists can now test a baby for genetic disease if the paternity is not known

By Daily Mail Reporter

PUBLISHED: 13:00 EST, 4 July 2012 | UPDATED: 13:00 EST, 4 July 2012

Scientists have mapped the complete DNA of an unborn baby - using just the mother's blood.

The breakthrough could allow doctors to test for a range of genetic diseases in future such as cystic fibrosis and Down's syndrome without the need of the father.

It follows a similar study reported last month which required which successfully sequenced a foetus' genome from the mother's blood, along with a sample of saliva from the father.

Routine? Scientists say the discovery brings foetal genetic testing closer to becoming an every day procedure

This time researchers at the University of Stanford in California managed the task using material only found circulating in the mother's blood.

Current techniques used to pick up genetic diseases in unborn babies require invasive sampling, which carries certain risks to the health of the mother and child.

But early diagnosis of such problems can allow doctors to pre-empt whether treatments are needed immediately after a baby is born.

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DNA of unborn baby mapped from just mother's blood paving way for new genetic disease screening

General News of Tuesday, 3 July 2012

Source: Daily Graphic

The DNA Centre at the Korle-Bu Teaching Hospital says it has the facilities to assist the law enforcement agencies in the detection of crime.

It said its machines could determine the identity of criminals by extracting DNA from saliva, hair, blood, semen or any other bodily fluid left at a crime scene or on the victims by the perpetrators.

The Director of the centre, Dr Bartholomew Dzudzor, told the Daily Graphic that unfortunately, however, officials at the centre had not been trained in the collection of forensic samples from crimes, adding that the centre would be willing to partner the police if the police could perform that task.

He explained that during the commission of violent crimes, such as murder, kidnapping, rape and robbery, minute traces of blood and other bodily fluids, as well as hair, were left at the crime scene.

He said what was needed was well-trained forensic experts to carefully collect those samples, adding that extreme caution was essential to ensure that the samples were not contaminated.

According to him, DNA extracted from the samples would then be compared to the DNA of suspects and if they matched, the suspects could then be charged with the crime.

"DNA may point at an individual and yet he or she may not be the perpetrator of the crime only if he or she was a homozygous (identical) twin," he said, adding that homozygous twins were formed from the same egg and, therefore, had similar DNA. "Even if he or she is a twin, the police could easily establish where they were at the time the crime was committed and, thereby, establish which of them committed the crime," he noted.

Dr Dzudzor said it would have been easier if the country had a DNA database or if the police had DNA profiles of people who lived close to crime scenes.

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Korle-Bu DNA Centre to help unravel crime

THE cost of DNA testing appears to be behind Australian Wool Innovation cutting off funds to its nucleus flock.

In a letter to its levypayers AWI said cost would deter DNA testing by stud breeders.

"The cost of genotyping is currently in the order of $130 and would have to drop to about $20 before a significant uptake is expected, " AWI chief executive Stuart McCullough and chairman Wal Merriman said in the letter.

Late last year AWI was asked to contribute $4.8 million to a nine-year program costing almost $13 million and involving a 6000-head flock joined over five years and four subsequent years of measurements.

At the time the Sheep Co-operative Research Centre paid $150 for a test that provided a parentage, detection of single gene traits such as pollness and predictions for a range of traits for wool and carcass quality, fertility and parasite resistance.

But Victorian Department of Primary Industries geneticist Dr Ben Hay said DNA costings were falling sharply worldwide.

Dr Hay said the cost of reading DNA had dropped by more than $100 in the past five years.

"And we can expect even greater reductions in the next couple of years," Dr Hay said.

Although AWI quoted a $130 test cost in its letter of last week, Sheep CRC chief executive Dr James Rowe said it had contracted a price of $110 for this year's pilot program and stud breeders would pay a subsidised rate of $50.

"We reckon it will be down to $50 next year," he said.

More here:
AWI not OK with DNA

Health News of Tuesday, 3 July 2012

Source: Daily Graphic

The DNA Centre at the Korle-Bu Teaching Hospital says it has the facilities to assist the law enforcement agencies in the detection of crime.

It said its machines could determine the identity of criminals by extracting DNA from saliva, hair, blood, semen or any other bodily fluid left at a crime scene or on the victims by the perpetrators.

The Director of the centre, Dr Bartholomew Dzudzor, told graphic.com.gh that unfortunately, however, officials at the centre had not been trained in the collection of forensic samples from crime scenes, adding that the centre would be willing to partner the police if the police could perform that task.

He explained that during the commission of violent crimes, such as murder, kidnapping, rape, robbery, among other things, minute traces of blood and other bodily fluids, as well as hair, were left at the crime scene.

He said what was needed was well-trained forensic experts to carefully collect those samples, adding that extreme caution was essential to ensure that the samples were not contaminated.

According to him, DNA extracted from the samples would then be compared to the DNA of suspects and if they matched, the suspects could then be charged with the crime.

DNA may point at an individual and yet he or she may not be the perpetrator of the crime only if he or she was a homozygous (identical) twin, he said, adding that homozygous twins were formed from the same egg and, therefore, had similar DNA.

See original here:
Korle Bu DNA Centre to help unravel crimes

NEW YORK, July 3, 2012 /PRNewswire/ --Reportlinker.com announces that a new market research report is available in its catalogue:

Global DNA Probes-Based Diagnostics Industry

http://www.reportlinker.com/p098404/Global-DNA-Probes-Based-Diagnostics-Industry.html#utm_source=prnewswire&utm_medium=pr&utm_campaign=Diagnosti

This report analyzes the worldwide markets for DNA Probes-based Diagnostics in US$ Million by the following Application Areas: Infectious Diseases, Cancer Testing, Genetic Predisposition, Identity/Forensics, Molecular HLA (Human Leukocyte Antigen) Typing, and Others. The report provides separate comprehensive analytics for the US, Canada, Japan, Europe, Asia-Pacific, and Latin America. Annual estimates and forecasts are provided for the period 2009 through 2017. Also, a six-year historic analysis is provided for these markets. The report profiles 63 companies including many key and niche players such as Abbott Laboratories, Affymetrix, Inc., Becton, Dickinson & Company, Beckman Coulter, Inc., bioMerieux, Celera Group, Gen-Probe Incorporated, Genzyme Corporation, Luminex Molecular Diagnostics, QIAGEN, Roche Diagnostics, and Siemens Healthcare Diagnostics, Inc. Market data and analytics are derived from primary and secondary research. Company profiles are primarily based upon search engine sources in the public domain.

I. INTRODUCTION, METHODOLOGY & PRODUCT DEFINITIONSStudy Reliability and Reporting Limitations I-1Disclaimers I-2Data Interpretation & Reporting Level I-3Quantitative Techniques & Analytics I-3Product Definitions and Scope of Study I-3Infectious Diseases I-4Cancer I-4Genetic Predisposition I-4Identity/Forensics I-4Molecular HLA Testing I-4Other Diagnostic Applications I-4II. EXECUTIVE SUMMARY

1. MARKET DYNAMICS II-1

Industry Overview II-1

DNA Probes: Robust Growth Ahead II-1

Decoding the Genetic Puzzle II-1

Advantages of DNA-Probe Tests II-2

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Global DNA Probes-Based Diagnostics Industry

ScienceDaily (July 2, 2012) Scientists say they have assembled more completely the string of genetic letters that could control how well parrots learn to imitate their owners and other sounds.

The research team unraveled the specific regions of the parrots' genome using a new technology, single molecule sequencing, and fixing its flaws with data from older DNA-decoding devices. The team also decoded hard-to-sequence genetic material from corn and bacteria as proof of their new sequencing approach.

The results of the study appeared online July 1 in the journal Nature Biotechnology.

Single molecule sequencing "got a lot of hype last year" because it generates long sequencing reads, "supposedly making it easier to assemble complex parts of the genome," said Duke University neurobiologist Erich Jarvis, a co-author of the study.

He is interested in the sequences that regulate parrots' imitation abilities because they could give neuroscientists information about the gene regions that control speech development in humans.

Jarvis began his project with collaborators by trying to piece together the genome regions with what are known as next-generation sequencers, which read chunks of 100 to 400 DNA base pairs at a time and then take a few days to assemble them into a draft genome. After doing the sequencing, the scientists discovered that the read lengths were not long enough to assemble the regulatory regions of some of the genes that control brain circuits for vocal learning.

University of Maryland computational biologists Adam Phillippy and Sergey Koren -- experts at assembling genomes -- heard about Jarvis's sequencing struggles at a conference and approached him with a possible solution of modifying the algorithms that order the DNA base pairs. But the fix was still not sufficient.

Last year, 1000 base-pair reads by Roch 454 became available, as did the single molecule sequencer by Pacific Biosciences. The Pacbio technology generates strands of 2,250 to 23,000 base pairs at a time and can draft an entire genome in about a day.

Jarvis and others thought the new technologies would solve the genome-sequencing challenges. Through a competition, called the Assemblathon, the scientists discovered that the Pacbio machine had trouble accurately decoding complex regions of the parrot, Melopsittacus undulates, genome. The machine had a high error rate, generating the wrong genetic letter at every fifth or sixth spot in a string of DNA. The mistakes made it nearly impossible to create a genome assembly with the very long reads, Jarvis said.

But with a team, including scientists from the DOE Genome Science Institute and Cold Spring Harbor in New York, Phillippy, Koren and Jarvis corrected the Pacbio sequencer's errors using shorter, more accurate codes from the next-generation devices. The fix reduces the single-molecule, or third-generation, sequencing machine's error rate from 15 percent to less than one-tenth of one percent.

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DNA sequenced for parrot's ability to parrot

The key to Angelines true identity remains elusive (File Photo)

MANILA, Philippines It seems singer Angeline Quintos quest to find her biological mother has not yet come to an end.

Although frustrated and emotional after the recent DNA test she underwent together with Veronica Tolentino, the woman claiming to be her biological mom, came back negative, Quinto vowed to continue searching for her real mother.

Sabi ko nga po sa tatay ko, tulungan niyo rin naman po ako na sana may magawa rin siya para makita namin ang totoo kong nanay, Quinto shared in a taped interview with The Buzz aired on July 1.

Aside from Tolentino, Quintos father Pop Quiros, also subjected himself to a DNA testing. Unlike Tolentino, the test yielded a positive result for Quiros, which means that shes Quintos biological father.

Natutuwa po ako na si Papa ko talagang tatay ko po at siyempre 'yung mga nakilala ko po na mga kapamilya ko simula noong bata ako, talagang kapamilya ko po, she said.

However, Quinto, for her part, felt sorry that she got a negative result when her DNA was cross-examined with Tolentinos.

Nakita niyo naman po kung ano ang reaction ni Aling Veronica, talagang umiyak siya noong niyakap niya ako. Sabi ko nga po, Pasensya na po kayo, siguro po ganoon talaga, the singer recalled.

Feeling for Tolentino, Quinto related that shes praying for her to eventually find her own biological daughter whom shes been searching for, for so long.

As for her own search, Quinto vowed that this is not the end; just the beginning of yet another chapter.

Originally posted here:
DNA Results Negative For Angeline Quinto, Purported Mother

A few strands of DNA could help solve the mystery of dark matter. A newly proposed detector aims to use DNA to resolve the conflicting claims from current dark matter detectors.

Dark matter is thought to make up about 85 per cent of the matter in the universe. The prime suspects are so-called weakly interacting massive particles, which are immune to the electromagnetic and strong nuclear forces. In theory, WIMPs interact with normal matter only via gravity and the weak nuclear force.

Attempts to detect WIMPs on Earth have provided conflicting results. On the positive front, two experiments CoGeNT in Soudan, Minnesota, and DAMA/LIBRA at Gran Sasso, Italy have seen more putative dark matter particles hitting their detectors in June than in December. All else being equal, the excess is attributed to Earth's relative velocity through the sea of dark matter that fills our galaxy. In June, Earth is moving in the same direction as the sun and so encounters a "headwind" of dark matter, the theory goes. In December, Earth, in its orbit around the sun, is moving in the opposite direction.

But, crucially, other bigger and more sensitive experiments, such as CDMS-II and XENON1O0, have seen no such particles. One way to resolve the conflict would be to detect the directionality of dark matter particles, to see if they are indeed aligned with the direction of the sun's motion through the galaxy, as required by DAMA/LIBRA and CoGeNT.

Now Andrzej Drukier of Biotraces a biotech firm based in Herndon, Virginia and a group of cosmologists and biochemists are suggesting that DNA could help break the impasse.

Their proposed detector consists of a 1-metre-square sheet of gold foil and a "forest" of single-strand DNA molecules suspended beneath in an ordered array, like the bristles on a toothbrush. When a WIMP strikes a gold atom in the foil, it would dislodge a gold nucleus and send it careening through the array, severing the DNA strands along its path. Energetic particles like cosmic rays have been shown to collide with and break strands of DNA, though WIMPs would have much lower energy.

The broken DNA strands would be gathered, amplified and analysed to determine exactly where each strand was severed. Given that the sequence of bases that make up each DNA strand is well known, the location of the cut on each strand and hence the path of the gold nucleus could be tracked to within a nanometre in three dimensions, around 1000 times better resolution than current detectors.

"The higher resolution means that we would get more data per WIMP event," says team member George Church of Harvard University.

Such 3D resolution would allow cosmologists to infer the both the energy and the direction of a WIMP, which could in turn confirm the existence of the predicted "WIMP wind" created by the solar system's motion through the galaxy.

A DNA-based detector has other advantages too, the team claims. It can operate at room temperature, as opposed to near absolute zero for current detectors. And by changing the material of the foil, it can be tuned to look for particles of different energies, including the WIMPs apparently detected by CoGeNT and DAMA/LIBRA. The team is now testing the feasibility of the design.

Read more from the original source:
Humble DNA could help decipher dark matter

Perhaps the greatest and most fiercely contested race in modern science is the search for dark matter.

Physicists cannot see this stuff, hence the name. However, they infer its existence because they can see its gravitational influence on the structure of galaxies and clusters of galaxies. It implies that the universe is filled with dark matter, much more of it than the visible matter we can see

If they're right, dark matter must fill our galaxy and our Solar System. At this very instant, we ought to be ploughing our way through a dense sea of dark matter as the Sun moves towards the constellation of Cygnus as it orbits the galactic centre.

That's why various groups are racing to detect this stuff using expensive detectors in deep underground caverns, which shield them from radiation that would otherwise swamp the signal.

These experiments are looking for the unique signature that dark matter is thought to produce as a result of the Earth's passage around the Sun. During one half of the year, the dark matter forms headwind as the Earth ploughs into it; for the other half of the year, it forms a tailwind.

Indeed, a couple of groups claim to have found exactly this diurnal signature, although the results are highly controversial and seem to be in direct conflict with other groups who say they have not seen it.

There's a a straightforward way to make better observations that should solve this conundrum. The dark matter signal should vary, not just over the course of a year, but throughout the day as the Earth rotates.

The dark matter headwind should be coming from the direction of Cygnus, so a suitable detector should see the direction change as the Earth rotates each day.

There's a problem, however: nobody has built a directional dark matter detector.

That's why a revolutionary new idea from an unlikely collaboration of physicists and biologists looks rather exciting. The group brings together diverse people, such as Katherine Freese at the University of Michigan in Ann Arbor, an astrophysicist and one of the leading thinkers in the area of dark matter, and George Church at Harvard University in Cambridge, a geneticist and a pioneer in the area of genome sequencing.

Link:
How A 'DNA Tracking Chamber' Could Detect Dark Matter

Perhaps the greatest and most fiercely contested race in modern science is the search for dark matter.

Physicists cannot see this stuff, hence the name. However, they infer its existence because they can see its gravitational influence on the structure of galaxies and clusters of galaxies. It implies that the universe is filled with dark matter, much more of it than the visible matter we can see

If they're right, dark matter must fill our galaxy and our Solar System. At this very instant, we ought to be ploughing our way through a dense sea of dark matter as the Sun moves towards the constellation of Cygnus as it orbits the galactic centre.

That's why various groups are racing to detect this stuff using expensive detectors in deep underground caverns, which shield them from radiation that would otherwise swamp the signal.

These experiments are looking for the unique signature that dark matter is thought to produce as a result of the Earth's passage around the Sun. During one half of the year, the dark matter forms headwind as the Earth ploughs into it; for the other half of the year, it forms a tailwind.

Indeed, a couple of groups claim to have found exactly this diurnal signature, although the results are highly controversial and seem to be in direct conflict with other groups who say they have not seen it.

There's a a straightforward way to make better observations that should solve this conundrum. The dark matter signal should vary, not just over the course of a year, but throughout the day as the Earth rotates.

The dark matter headwind should be coming from the direction of Cygnus, so a suitable detector should see the direction change as the Earth rotates each day.

There's a problem, however: nobody has built a directional dark matter detector.

That's why a revolutionary new idea from an unlikely collaboration of physicists and biologists looks rather exciting. The group brings together diverse people, such as Katherine Freese at the University of Michigan in Ann Arbor, an astrophysicist and one of the leading thinkers in the area of dark matter, and George Church at Harvard University in Cambridge, a geneticist and a pioneer in the area of genome sequencing.

Visit link:
Revolutionary 'DNA Tracking Chamber' Could Detect Dark Matter

Scientists find that declining DNA methylation in mouse neurons may cause age-related memory deficits.

Researchis increasingly connecting changes in epigenetic regulation of gene expression to the aging process. Many studies demonstrate that DNA methylation declines with age. Now, new research published yesterday (July 1) in Nature Neuroscience links DNA methylation with brain aging. Researchers show that levels of an enzyme that attaches methyl groups to cytosine nucleotides throughout the genome is linked to cognitive decline, and that its overexpression can restore performance of aging mice on memory-related tasks.

We already know normal aging is associated with cognitive decline, but this paper links that with expression a specific DNA methyltransferase, said Yuan Gao, an epigeneticist at the Lieber Institute for Brain Development in Maryland, who did not participate in the study. The current work also builds on other studies demonstrating that proper regulation of methylation in brain cells is critical to memory formation. Previous studies have suggested a connection between loss of DNA methylation and Alzheimers disease, said Gao, suggesting that if researchers could restore [methyltransferase] activity and cure or delay dementia, it would make a nice model for developing drugs to tackle age-related cognitive diseases.

DNA methylation, wherein a methyl group is attached to a cytosine next to a guanosine, is one form of epigenetic regulation that can modulate how available genes are to the cells transcription machinery, and thus how highly expressed they are. Scientists already appreciate how differences in epigenetic regulation can affect development of diseases like cancer, without need for gene mutations. Studies are also accumulating that correlate declining methylation with aging, although the mechanism remains unclear.

Classically, DNA methylation is considered a repressive modification, but that view is beginning to change, suggesting a more nuanced role for methylation in gene regulation, explained senior author Hilmar Bading of the University of Heidelberg. The twist in Badings current research is that the methyltransferase his group focuses on, Dnmt3a2, may be working to enable gene transcription, rather than repress it.

This gene-activating role may stem from methylation that blocks repressors, rather than activators, explained Trygve Tollesfbol, who investigates the role of epigenetics in cancer and aging at the University of Alabama, who did not participate in the research. Whether methylation is located in the promoter or body of the gene can also determine whether it inhibits or enhances transcription, explained Guoping Fan, who studies epigenetic regulation of neuron development at the University of California, Los Angeles.

Badings group identified Dnmt3a2 when looking for genes that are upregulated by neuronal activity. Knowing that DNA methylation decreases with age, first author Ana Oliviera compared Dnmt3a2 expression in 3-month-old and 18-month-old mice, and found lower levels of Dnmt3a2 in the older mice. Furthermore, learning tasks designed to stimulate hippocampus neurons failed to upregulate Dnmt3a2 expression in old mice as robustly as in young mice.

Theorizing that reduced Dnmt3a2-dependent DNA methylation contributed to older mices poorer performance on learning and memory tasks, the scientists used an adeno-associated virus to supplement Dnmt3a2 expression in their hippocampal neurons. Boosting its expression enhanced both brain methylation in the older mice, and their ability to learn. Conversely, when the researchers used short hairpin RNA to knockdown Dnmt3a2 expression in young mice, their performance on learning and memory tests worsened.

I think Dnmt3a2 has a basic gating function, said Bading. Neurons need to turn genes on and off quickly in response to changing stimulation. Bading hypothesizes that Dnmt3a2-dependent methylation helps keep geneslike brain-derived neurotrophic factor (BDNF) and Arc, both regulated by Dnmt3a2 and both involved in responses to signaling changesreceptive to changing stimulation, putting the genome in the right state for being inducible, Bading said. Genes like BDNF shouldnt be transcribed all the time, but it may be that without Dnmt3a2-dependent methylation, the door is closed neurons cant express them when they need to.

This could set up a vicious cycle, Bading explained, because Dnmt3a2 is also induced by neuronal activity. Less Dnmt3a2 would result in less expression of methylation-dependent genes, possibly including Dnmt3a2 itself, and the effect would worsen over time. It would take many years to add up, but aging takes years, Bading noted.

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DNA Methylation Linked to Memory Loss

MANILA, Philippines The DNA test conducted on Angeline Quinto and Veronica Tolentino, the woman who claims to be the singers biological mom, turned out to be negative.

Quintos DNA, however, matched that of her father Pop Quiros, according to The Buzz.

In an interview with the ABS-CBN talk show which aired on Sunday, Quinto said she had mixed emotions when she learned about the DNA test results.

Natutuwa po ako na si Papa ko talagang tatay ko po at siyempre 'yung mga nakilala ko po na mga kapamilya ko simula noong bata ako, talagang kapamilya ko po. Pero siyempre may halo rin pong lungkot kasi nakita niyo naman po kung ano ang reaction ni Aling Veronica, talagang umiyak siya noong niyakap niya ako, she said.

While she vows to continue searching for her biological mom, Quinto also hopes that Tolentino will eventually find her real daughter.

Sabi ko nga po pasensya na po kayo, siguro po ganoon talaga. Tapos tinatanong niya po ako bakit daw ganun, alam daw po kasi niyang talagang anak nyia ako. Naiyak nga rin po ako kanina pero pinigilan ko kasi ayaw kong makita niya, she said.

Asked what she wants to tell her mother if she happens to be watching, Quinto said: Sana po kung nagdadalawang isip pa kayong magpakita sa akin... huwag po kayo mag-alala kasi naiintindihan ko naman na po lahat iyon kahit na sumama ang loob ko sa inyo nung bata ako. Matagal ko na kayong gustong makilala kahit makita ko lang po.

Meanwhile, Tolentino said she will forever consider Quinto as her daughter. She also hopes the singer will never be changed by fame.

Mabigat sa loob ko kasi nga alam ko talaga anak kita. Parang hindi ko makaya. Para akong binagsakan ng lupat langit. Pero anak, anak pa rin ang tawag ko sa iyo, huwag mo na lang ipagkait. Sana huwag ka magbago, she said.

Tolentino also thanked Quinto for going out of her way just to have the DNA test conducted.

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DNA test on Angeline, supposed mom negative

Jun 30 2012 By Janice Burns

ian kinnaird Image 2

A SCOTS pensioner has been told he is a direct descendant of Eve, the first woman on Earth.

Ian Kinnaird, 72, who took a DNA test to trace his ancestors, was gobsmacked when researchers phoned to tell him he could have descended directly from the Garden of Eden.

They told him he was the grandson of Eve, or grandfather of everyone in Britain.

The results showed Ian has a genetic marker, L1B1, that can be traced all the way to an ancient African lineage.

It has never before been found in Western Europe.

Widower Ian, of Halkirk, Caithness, has mitochondrial DNA (mtDNA), which is passed through the female side, is 30,000 years old and only two genetic mutations removed from the first black Eve.

The retired lecturer said: Ive led an unremarkable life until now. This is a real gobsmacker.

I seem to carry a gene from West Africa that arrived through the slave trade.

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DNA tests reveal Scots pensioner's roots go back to origins of man