Toshiba prices its new tablet to undercut Apple's ipad2

The growing popularity of tablets has seen many new players enter the market

Toshiba has announced its foray into the fast-growing tablet market with its latest gadget called Thrive.

The Japanese electronics maker has priced its entry level model at $429 (£262), which is cheaper than the base model of Apple's ipad2.
The company said its base model comes with wi-fi ability and is targeted at consumers who use tablets at home.
The tablet will go on sale in the US on 10 July.
'Non-Apple products'
The success of Apple's ipad has encouraged many computer and electronics companies to enter the segment.
Samsung has launched its Galaxy tab, while Sony has also announced its entry with two new models.
While none of them have been able to make a significant dent in Apple's market share, Toshiba said demand for other products was increasing gradually.
"There is a market out there of folks who want to buy non-Apple products," said Jeff Barney of Toshiba America.

David Tennant and Catherine Tate win over critics

Reunited former Doctor Who stars David Tennant and Catherine Tate's Much Ado About Nothing has opened in the West End to a largely positive reception from critics.

Josie Rourke's production transports Shakespeare's comedy to 1980s sun-drenched Gibraltar - complete with Rubik's Cubes and disco dance floors.
Tennant and Tate portray reluctant lovers Beatrice and Benedick.
The Guardian's Michael Billington said the casting "pays off superbly".

David Tennant's Benedick time travels to the 1980s in this production.

The production at Wyndham's Theatre comes only a few days after a more traditional take on Much Ado opened at Shakespeare's Globe to rave reviews.
Billington called Rourke's adaptation "more socially specific and much sexier".
His review adds: "The pairing of David Tennant as Benedick with Catherine Tate as Beatrice is a marriage that, if not made in heaven, is certainly cemented by television and pays off superbly."
Telegraph critic Charles Spencer described the production as a "populist Shakespeare with both intelligence and heart".
He said: "Purists will doubtless baulk, but there is an outstanding traditional production of Much Ado now playing at the Globe, and Rourke's production has a freshness and wit about it that is often irresistible.
"The chemistry Tennant and Tate established in Dr Who survives in their performances as the disputatious lovers."
Golf buggy
Director Rourke loads the play's first half with a string of slapstick scenes before events take a tragic turn at the wedding of Claudio (Tom Bateman) and Hero (Sarah MacRae).

Catherine Tate adopts several of her comedy voices for the role of Beatrice.

Tennant, who makes his entrance in a crisp white naval uniform driving a golf buggy, is no stranger to Shakespeare, despite being best known as a TV Time Lord. He appeared in Love Labour's Lost and Hamlet in 2008.
He played the 10th incarnation of the Doctor in the BBC sci-fi show until the end of 2009, with Tate as his companion Donna Noble.
Among the audience on Wednesday night was Tennant's earlier Tardis companion Billie Piper.
Tate, in particular, is given plenty of opportunity to use her comedy talents, although she did not win over all the critics.
In his review for The Arts Desk, James Woodall said: "Beatrice should, or can, be skittish, flirtatious and unpredictable. Tate is matter-of-fact, hard-nosed and static.
"She has one basic gesture, and that's finger-pointing. Her accent slews all over the place, from courtly posh to estuary - familiar of course from her screen comedy - and throughout it's as if she's just one step or chortle or guffaw away from the parody and mockery, the self-mockery, that make her TV characters so compelling."
'Warmth of wit'
While he has high praise for Tennant, The Independent's Paul Taylor opts for the Globe's alternative Much Ado as the superior production:

The Globe's Much Ado About Nothing - starring Charles Edwards and Eve Best - opened last week to strong reviews.

His three-star review says: "This indoor, proscenium-arch account of the play fails to match - in confidence, sprezzatura, warmth of wit, or understanding of the heart - the version that opened last week at Shakespeare's Globe. A rare misstep for the admirable Josie Rourke, this production feels effortful and inauthentic."
The Globe's Much Ado, which opened to a string of four-star reviews, stars Eve Best and Charles Edwards as Beatrice and Benedick and is directed by Jeremy Herrin.
Much Ado About Nothing at the Wyndam's Theatre is booking until 3 September. The Shakespeare's Globe production is on until 1 October.

DNA computer 'calculates square roots'

DNA computing is just one of several "biological computing" approaches

Researchers have shown off a "DNA computer" of unprecedented complexity, which can calculate square roots.

DNA computing uses chemical reactions to solve problems in which a number of DNA strands act as "bits".
The work, reported in Science, required 130 strands of DNA to work in a cascade of programmed chemical changes.
The approach is not designed to rival traditional electronics, but rather to allow computing to occur in biological contexts, perhaps even in the body.
DNA computing was first proposed by Leonard Adelman in 1994, to solve what is known as the "travelling salesman problem" - determining the shortest path that joins a number of geographically separated locations.
Since then, a wide array of approaches has aimed to make use of the properties that make DNA attractive for computing: it can be made to order and its interactions with itself are well-studied and reliable.
In 2006, Erik Winfree of the California Institute of Technology (Caltech) and his colleagues published an article in Science a framework making use of one of these approaches, known as strand displacement.
Stretches of DNA made of just one strand (rather than the two joined strands that form the well-known double helix) were used as anchor points for other single strands.
By carefully "programming" the movement of these strands, the researchers were able to recreate a number of elements familiar from conventional computing, including logic gates, amplification, and feedback.
"Those circuits were smaller [than those of the current work], but more importantly, they were built using more complex DNA molecules that made systems more difficult to debug and had other problems," Professor Winfree told BBC News.
Stranded
Now, Professor Winfree and his collaborator Lulu Qian have employed a scheme using what they call "seesaw gates", which accomplish the shuffling and exchange of DNA strands using simpler machinery.

The work showed that seesaw gates could again be used to create logic gates - the basis of electronic computing's manipulation of information - and represented a five-fold leap in the number of DNA sections ever implemented in such a DNA computer.

The approach can be scaled up in complexity far further, the authors suggest - but the process is slow.
For example, it was used to calculate the square root of a four-bit number, but the process took between six and 10 hours.
However, Professor Winfree said that contrary to conventional electronics, the goal is not just high speeds.
"We are no longer pursuing the goal targeted by Len Adleman's original DNA computing experiment: to compete with silicon by using the massive parallelism of chemistry to solve combinatorial problems in mathematics," he explained.
"Instead, our goal is now - and has been for many years - to enrich chemistry itself so that molecular behaviours can be programmed.
"We'd like to make chemical systems that can probe their molecular environments, process chemical signals, make decisions, and take actions at the chemical level."
Binyamin Gil, a member of the research group that in 2009 published on a DNA computer that could "answer" logical conundrums, told BBC News that the DNA computer of the new work exhibited more "digital behaviour" than other molecular computing approaches and thus that "it may be more robust, reliable and scalable".
"The complexity of the presented work - together with the potential of scalability and of interfacing it with other molecular computers - make this paper important and interesting," he said.

DNA tests for Argentine Clarin group heirs

Marcela and Felipe say they have no wish to discover their birth families

An Argentine court has ruled that the heirs to the country's main media group must submit to DNA-testing, to see if they were born to left-wing prisoners killed by the military in the 1970s.

Judges ruled that Marcela and Felipe Noble Herrera - adopted children of the Clarin Group owner - must give direct samples such as blood or saliva.
They will be compared with samples on a genetic database linked to the missing.
The siblings object to the tests. Their mother says their adoption was legal.
Campaigners have said previous samples given by the siblings were not adequate for testing.
These include blood samples the siblings gave in 2009 at a federal agency, but not the National Bank of Genetic Data.
The issue of babies taken from prisoners during the country's so-called Dirty War is a highly emotive one in Argentina.
Several hundred babies are believed to have been taken from their detained parents and given to families loyal to the military during its 1976-83 rule.
Groups like the Grandmothers of the Plaza de Mayo, who campaign on behalf of people who were "disappeared" by the military, have helped a number of children locate their biological relatives.
In 2009, Argentina's congress passed a measure allowing forcible extraction of DNA in such cases, even when the people concerned do not want to discover their past.
Forced sell-off
The Noble Herrera siblings claim their rights have been violated.
They say their DNA is private, that they have no desire to trace their biological parents, and that they are victims of political persecution.
In recent years, the media group owned by their adoptive mother, Ernestina Noble Herrera, has been staunchly opposed to the current government of President Cristina Fernandez de Kirchner.
In 2009, President Fernandez succeeded in driving through legislation that forced Clarin to sell off parts of its media empire.
The BBC's Vladimir Hernandez in Buenos Aires says the latest verdict could put an end to a court battle that has lasted some 10 years.
But, he adds, the decision could stir up a political storm.
The siblings could still appeal to the Supreme Court.
But if the tests are carried out and prove the Noble Herreras were taken from detainees, their adoptive mother could face a criminal investigation.

Groupon share offer to raise up to $750m

Groupon has 83 million members around the world

Daily discount website Groupon is seeking to raise up to $750m (£460m) in an initial public offering (IPO).

It is the latest move by an internet company seeking to cash in on investor appetite for social media firms.
Last month, business networking site LinkedIn saw its shares more than double in value on their first day of trading after the company went public.
IPOs are when companies list their shares on the stock market for the first time.
Groupon offers daily discounts to members on items ranging from meals out and beauty treatments to flying lessons.
The offers are typically available for a set period and for a limited number of buyers.
Groupon then takes a commission of 30-50% from the merchants who provide the services.
The company has 83 million members in 43 countries and employs more than 7,000 staff.
'Twists and turns'
Groupon was founded in November 2008 and is yet to make a net profit.
It brought in revenues of $644.7m in the first quarter of 2011, but made a net loss of $146.5m after investing in growth, especially overseas.
In December it turned down a $6bn takeover offer from Google.
"As with any business in a 30-month-old industry, the path to success will have twists and turns, moments of brilliance and other moments of sheer stupidity," Groupon chief executive Andrew Mason said in a letter to potential shareholders that was attached to the IPO filing.
The filing did not specify the number of shares to be sold, the price range, or the stock exchange it would list on.
But it did say shares would trade under the symbol "GRPN".