Category Archives: DNA

DNA is the blueprint for life. Could it also become the template for making a new generation of computer chips based not on silicon, but on an experimental material known as graphene? Thats the theory behind a process that Stanford chemical engineering professor Zhenan Bao reveals in Nature Communications.

Bao and her co-authors, former post-doctoral fellows Anatoliy Sokolov and Fung Ling Yap, hope to solve a problem clouding the future of electronics: consumers expect silicon chips to continue getting smaller, faster and cheaper, but engineers fear that this virtuous cycle could grind to a halt. Why has to do with how silicon chips work.

Everything starts with the notion of the semiconductor, a type of material that can be induced to either conduct or stop the flow of electricity. Silicon has long been the most popular semiconductor material used to make chips.

The basic working unit on a chip is the transistor. Transistors are tiny gates that switch electricity on or off, creating the zeroes and ones that run software.

To build more powerful chips, designers have done two things at the same time: theyve shrunk transistors in size and also swung those gates open and shut faster and faster.

The net result of these actions has been to concentrate more electricity in a diminishing space. So far that has produced small, faster, cheaper chips. But at a certain point, heat and other forms of interference could disrupt the inner workings of silicon chips.

"We need a material that will let us build smaller transistors that operate faster using less power," Bao said.

Graphene has the physical and electrical properties to become a next-generation semiconductor material if researchers can figure out how to mass-produce it.

Graphene is a single layer of carbon atoms arranged in a honeycomb pattern. Visually it resembles chicken wire. Electrically this lattice of carbon atoms is an extremely efficient conductor.

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Using DNA to assemble a transistor from graphene

Public release date: 10-Sep-2013 [ | E-mail | Share ]

Contact: Raquel Maurier rmaurier@ualberta.ca 780-492-5986 University of Alberta Faculty of Medicine & Dentistry

Medical researchers at the University of Alberta have made a basic science discovery that advances the understanding of how DNA repairs itself. When DNA becomes too damaged it ultimately leads to cancer.

Faculty of Medicine & Dentistry researcher Mark Glover and his colleagues published their findings in the peer-reviewed journal, Structure (Cell Press), earlier this summer. For years, scientists thought two key proteins involved in DNA repair operated in exactly the same way. Glover's team discovered how the proteins operate and communicate is vastly different information that could lead to improved cancer treatments.

Glover explains that a protein known as BRCA1 acts like a hallway monitor constantly scanning DNA for damage. At the first sign of problems, this protein figures out what kind of help is needed, and "radios" in a cleanup crew of other proteins.

A second protein, known as TopBP1, ensures that DNA can copy itself when needed. When this process stalls due to DNA damage, this protein also calls in a cleanup crew. But Glover likens its method of communication to tweets, rather than radio.

"The two proteins may be related and look very similar, but their roles and the way they communicate are in fact very different, which was surprising to us," Glover says. "Each protein plays a role in recognizing damaged regions of DNA, but the problem they each solve is different.

"The question now is how can we use this information to try to improve cancer therapies? Could we temporarily knock out cancer DNA's ability to repair itself from radiation damage? Could we administer radiation at a point that prevents cancer DNA from copying itself? Could we inhibit the activity of proteins that are normally trying to run around and fix the damage?

"Maybe some of these ideas could ultimately translate into less radiation or chemotherapy needed for patients, if the treatment can be more targeted," says Glover, who works in the Department of Biochemistry.

His team is continuing its research in this area, and wants to learn more about the role of the TopBP1 protein and why it favours communicating with a specific protein. They also want to conduct tests in their lab to see if the use of certain medications could alter the way these proteins work in a way that could result in new or improved cancer treatments.

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Discovery about DNA repair could lead to improved cancer treatments

Human remains found in a box in the rafters of a garage are those of a toddler last seen about three months ago inside a house on the same property, police said Tuesday.

DNA tests confirmed the skeletal remains are of 19-month-old Elaina Steinfurth, said Toledo police Sgt. Joe Heffernan.

Investigators found the remains last Thursday inside a box behind other containers and piles of trash in the detached garage's rafters. The home where the girl was last known to be alive belongs to the family of a man who had been dating the girl's mother.

Both the mother, Angela Steinfurth, and her now-estranged boyfriend, Steven King II, are in jail and accused of obstructing justice. Prosecutors will decide whether to file any additional charges, Heffernan said.

"They're not going anywhere, anytime soon," he said.

Steinfurth and her two daughters stayed with King at his family's home on June 1, investigators said. The girl's father went to the residence to pick up his two daughters the next day, but only Elaina's 4-year-old sister could be found.

Investigators have said Steinfurth knew Elaina had been seriously injured and didn't seek medical help. They would not say what type of injuries the toddler had or who caused them.

Steinfurth has been in jail since mid-June. Her attorney has declined to comment.

King was charged in July with lying to investigators about the child's disappearance. He told reporters after his arrest that he is innocent.

Authorities, including the FBI, and volunteers had searched homes, parks, vacant buildings and the Maumee River near downtown Toledo for any sign of Elaina.

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DNA Tests Confirm Remains Are Missing Ohio Toddler

Police are searching for a crime watch volunteer who they say has been connected by DNA to at least four sexual assaults in a South Dallas neighborhood in the past two months.

Authorities took Van Dralan Dixson, 38, into custody briefly last week and obtained a DNA sample from him, but lacked evidence to bring charges at the time, police Maj. Jeff Cotner said.

Three arrest warrants issued Monday and another on Saturday charge Dixson with aggravated sexual assault in four attacks in Fair Park, southeast of downtown Dallas. DNA test results from two other attacks were pending, while DNA evidence from two more in the inner-city neighborhood were not available, Cotner said.

Federal agents were assisting city police in the manhunt, and police have interviewed friends, family, and associates for clues to Dixson's whereabouts, Cotner said. Dixson's car was found abandoned in Garland, a northeastern Dallas suburb, and police have sought a warrant to search the vehicle, Cotner said.

As a crime-watch volunteer, Dixson would patrol the streets several times a week, neighbors said.

"He just walks every night, all night," one resident, Billy Washington, told Dallas television station WFAA. "Every time I would look out my window, or out my door, he was walking."

Dixson has been part of the area's neighborhood crime-watch group, the Mill City Community Association, since January. The group's president, Alendra Lyons, didn't return messages Monday from The Associated Press.

The group said Dixson's duties were limited to telling neighbors about the association, not patrolling at night. Neighbors told The Dallas Morning News that he was referred to as "neighborhood watch," and it seemed he was patrolling the area almost every night.

State criminal records show Dixson was arrested and convicted of aggravated robbery in 1993. He was also arrested as recently as last month on a deadly conduct charge, according to Dallas County records.

Authorities say they believe one man is responsible for the nine sexual assaults that have been reported in the Fair Park area since June. In each incident, the attacker approached his victims in the early morning hours, forced them to secluded areas nearby, then robbed and sexually assaulted them.

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Dallas Police Say DNA Links Suspect to Rapes

Barack Hussein Obama Cloned DNA Annunaki
This is a $ammy Daiana Presentation... We find evidence on several different aspects that President Barack Hussein Obama is not who he says he is . We are ...

By: MsOutlawTV

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Barack Hussein Obama Cloned DNA Annunaki - Video

A PBusardo Review - The DNA 20
A PBusardo Review -The DNA-20 Although I took a look at the DNA-20 in the Opus D review, I wanted a stand-alone DNA-20 video I could refer people to when loo...

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A PBusardo Review - The DNA 20 - Video

DNA Attack - Demi Lovato Vs Little Mix (Mashup)
Enjoy and comment, rate, like, subscribe in channel and share with friends 😀 " Copyright Disclaimer Under Section 107 of the Copyright Act 1976, allowance i...

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DNA Attack - Demi Lovato Vs Little Mix (Mashup) - Video

By David Simpson, CNN

updated 8:08 PM EDT, Sat September 7, 2013

STORY HIGHLIGHTS

(CNN) -- Dallas police Saturday said DNA evidence has provided a breakthrough in an investigation of nine sexual assaults in South Dallas this summer.

Police asked for the public's help in locating Van Dralan Dixson, 38, who is named in an arrest warrant for aggravated sexual assault. His DNA matched evidence gathered in one case, a police statement said. Samples for other cases are awaiting analysis.

Van Dralan Dixson's DNA matches evidence gathered in at least one case, police say.

Dallas police had said officers were "saturating" the area of the attacks and that a task force had been created to investigate the crimes.

Police have said a single suspect was believed responsible for attacks on nine victims from June 22 through September 1.

All of the victims were walking between midnight and 6 a.m. when an armed man forced them to nearby secluded areas. The victims were robbed and sexually assaulted.

Victims said the attacker covered his face with a mask or bandanna, CNN affiliate WFAA-TV reported.

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DNA match leads to search for suspect in Dallas sexual assaults

Hunting for Dinosaur DNA
From the BBC Horizon documentary Dinosaurs: The Hunt for Life, how Dr Mary Schweitzer found organic matter in ancient fossils.

By: lesterfontayne

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Hunting for Dinosaur DNA - Video

Public release date: 6-Sep-2013 [ | E-mail | Share ]

Contact: Steven Benowitz steven.benowitz@nih.gov 301-451-8325 NIH/National Human Genome Research Institute

The use of nanopore technology aimed at more accurate and efficient DNA sequencing is the main focus of grants awarded by the National Institutes of Health. The grants nearly $17 million to eight research teams are the latest awarded through the National Human Genome Research Institute (NHGRI)'s Advanced DNA Sequencing Technology program, which was launched in 2004. NHGRI is part of NIH.

"Nanopore technology shows great promise, but it is still a new area of science. We have much to learn about how nanopores can work effectively as a DNA sequencing technology, which is why five of the program's eight grants are exploring this approach," said Jeffery A. Schloss, Ph.D., program director for NHGRI's Advanced DNA Sequencing Technology program and director of the Division of Genome Sciences.

Nanopore-based DNA sequencing involves threading single DNA strands through tiny pores. Individual base pairs the chemical letters of DNA are then read one at a time as they pass through the nanopore. The bases are identified by measuring the difference in their effect on current flowing through the pore. For perspective, a human hair is 100,000 nanometers in diameter; a strand of DNA is only 2 nanometers in diameter. Nanopores used in DNA sequencing are 1 to 2 nanometers in diameter.

This technology offers many potential advantages over current DNA sequencing methods, said Dr. Schloss. Such advantages include real-time sequencing of single DNA molecules at low cost and the ability for the same molecule to be reassessed over and over again. Current systems involve isolating DNA and chemically labeling and copying it. DNA has to be broken up, and small segments are sequenced many times. Only the first step of isolating the DNA would be necessary with nanopore technology.

Innovation is crucial in these as well as the other (non-nanopore) studies being funded. For example, one research team eventually hopes to use light to sequence DNA on a cell phone camera chip for under $100.

The new grants are awarded to:

Dr. Aksimentiev and his colleagues plan to use nanopores as sensors. The researchers are studying the effects of combining synthetic nanopores with a light-based technique to control the flow of DNA molecules through the pores. They will use a type of spectroscopy to read the chemical sequence of the DNA.

Dr. Edwards and his colleagues plan to develop innovative molecular biology tools to improve whole-genome sequencing, which entails reading a person's entire genetic blueprint. The researchers hope that better methods of preparing the DNA molecules for sequencing will help scientists identify and link genetic variants to disease and, ultimately, lead to new treatments.

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New NIH awards focus on nanopore technology for DNA sequencing