Friday, February 3, 2012
Thursday, February 2, 2012
ScienceDaily (Feb. 1, 2012) ? Studying self-replicating genetic units, called plasmids, found in one of the world's widest-ranging pathogenic soil bacteria -- the crown-gall-disease-causing microorganism Agrobacterium tumefaciens -- Indiana University biologists are showing how freeloading, mutant derivatives of these plasmids benefit while the virulent, disease-causing plasmids do the heavy-lifting of initiating infection in plant hosts. The research confirms that the ability of bacteria to cause disease comes at a significant cost that is only counterbalanced by the benefits they experience from infected host organisms.
A. tumefaciens is widely studied for its remarkable biology not only because it causes disease in over 140 genera of broadleaf plants, including fruit trees, grapes, roses and walnut trees, but also because it is considered one of the most important tools for plant biotechnology: It is the only organism known to routinely engage in inter-kingdom lateral gene transfer. A. tumefaciens infects host plants by transferring a portion of its own DNA into plant cells, and this integrated bacterial DNA is expressed in the plant cells, leading diseased plants to develop tumors and produce resources that benefit the pathogen.
"We've identified two types of costs the plant pathogen A. tumefaciens pays for traits conferred by genes carried on plasmids," said lead author Thomas G. Platt, a postdoctoral researcher in the IU Bloomington College of Arts and Sciences' Department of Biology. "There is a relatively low cost of maintaining the tumor-inducing virulence plasmid, but there is also a dramatically large cost of expressing the genes that are required to infect plants."
Plants with crown gall disease can also benefit a second type of plasmid that can be found in A. tumefaciens: Nonpathogenic plasmids that lack the genes required to infect plants, yet are still able to benefit from the breakdown of nutrient resources released by infected plant tissue.
"These nonvirulent strains are able to freeload on public goods produced by host plants infected by their disease-causing relatives, while themselves avoiding the burdens associated with A. tumefaciens' virulence plasmid," Platt explained. "And our results suggest that at least one source of the selective pressure favoring the spread of these avirulent mutants stems from those high costs associated with the expression of the genes underlying pathogenesis."
Scientists are especially interested in freeloading or cheating strains of bacteria as a possible means of constraining infection caused by more aggressive, pathogenic strains. Creating something of a balancing act, mutant cheater strains may counter or constrain virulence as they maintain higher fitness by not having to invest in the cellular machinery virulent bacteria employ to infect hosts.
"The population dynamics and maintenance of bacterial plasmids depend on the costs they impose and benefits they confer on the cells that host them, and those costs and benefits are environmentally context dependent," Platt said. "The outcome of competition between two agrobacteria strains such as the ones we have been studying varies with the environmental conditions in which they are competing, and this genotype-by-genotype-by-environment interaction suggests that the virulence plasmid may be subject to selective pressures that vary over space and time."
Platt and IU biology professors James D. Bever and Clay Fuqua recently published the measured fitness costs imposed by plasmids to host cells, under certain environmental conditions, in the research article "A cooperative virulence plasmid imposes a high fitness cost under conditions that induce pathogenesis," that appeared in Proceedings of the Royal Society B. That work will be expanded upon in research accepted for publication in an upcoming edition of the journal Evolution, where the team further examines how cooperation benefits depend on resource availability and the importance of ecological dynamics, including resource consumption and population growth, on the evolution of cooperative traits.
Recommend this story on Facebook, Twitter,
and Google +1:
Other bookmarking and sharing tools:
The above story is reprinted from materials provided by Indiana University, via Newswise.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
- T. G. Platt, J. D. Bever, C. Fuqua. A cooperative virulence plasmid imposes a high fitness cost under conditions that induce pathogenesis. Proceedings of the Royal Society B: Biological Sciences, 2011; DOI: 10.1098/rspb.2011.2002
Note: If no author is given, the source is cited instead.
Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.
Wednesday, February 1, 2012
NEW YORK (Reuters) ? Qualcomm Inc's quarterly profit easily beat Wall Street forecasts and the wireless chip leader raised its full-year financial targets due to growing demand for smartphones such as Apple Inc's popular iPhone.
Shares in the biggest supplier of cellphone chips rose 5 percent after the company also said it has been winning business from rivals and is benefiting from growing demand for smartphones in emerging markets such as China.
Qualcomm, widely known as the main wireless chip supplier for the latest iPhone, was helped by the launch of the blockbuster device late last year, analysts said.
"It's a very strong result. The move to smartphones in the emerging markets in the success of the iPhone is driving its earnings higher," Canaccord Genuity analyst Mike Walkley said.
He said Qualcomm also generates hefty technology royalties from Apple, which does not disclose its chip suppliers.
Qualcomm appears to be taking business from rivals such as STMicroelectronics and Intel Corp, whose Infineon chip business has been a big supplier for the iPhone, Walkley said.
The company raised its revenue target for full-year 2012 to a range of $18.7 billion to $19.7 billion from its previous target of $18 billion to $19 billion.
Qualcomm also said it expects full-year earnings per share, excluding unusual items, of $3.55 to $3.75, up from its previous forecast for $3.42 to $3.62.
For its first fiscal quarter Qualcomm's earnings, excluding unusual items, of 97 cents per share were well ahead of Wall Street expectations for 90 cents according to Thomson Reuters I/B/E/S.
DISMISSES MARGIN CONCERNS
But even as they applauded the strong results and outlook, analysts on Qualcomm's conference questioned the company's ability to maintain profitability in its chip business since it faces pressure to cut chip prices as much of its growth is coming from phones that use less expensive chips.
Qualcomm Chief Financial Officer William Keitel said the company typically reduces chip prices for its customers every first quarter, noting that this would happen again this period.
But he said high sales volumes in countries like China will continue to offset lower prices and profit margins in these markets, ensuring revenue and earnings growth for at least the next five years for Qualcomm.
"That concern's been there three years now but each year investors have been pleasantly surprised," Keitel told Reuters. There's so much volume opportunity in the emerging markets what we're seeing is that the volume upside is more than compensating for the revenue and margin pressure."
While Qualcomm is seeing some pullback in smartphone demand in Europe, because of economic concerns there, the company said it is seeing strong growth in markets such the United States, Japan and South Korea.
In particular the company expects strong growth in these markets from smartphones using Long Term Evolution, an emerging high-speed wireless technology. Qualcomm expects LTE to represent a third of Qualcomm chip shipments by year-end, according to Keitel.
"They're in the right place at the right time on three major trends," Snyder said, referring to Qualcomm's strong position in China, in the market for LTE chips, and with Apple.
REGULATORY CORRUPTION PROBE
On the conference call Chief Executive Paul Jacobs also disclosed that U.S. and California regulators are investigating whether Qualcomm complies with the Foreign Corrupt Practices Act. But investors appeared to shrug off the announcement after Jacobs said he is confident the company is in compliance.
The preliminary investigation, which Qualcomm learned about January 27, was included in the company's quarterly report in a section discussing a whistleblower case brought against Qualcomm in 2010. Keitel would not discuss the case further.
San Diego, California-based Qualcomm reported a profit of$1.395 billion, or 81 cents per share, for its fiscal first quarter ended December 25, compared with a profit of $1.17 billion, or 71 cents per share, in the year-ago quarter.
Revenue rose to $4.68 billion from $3.35 billion, and compared with Wall Street expectations of $4.58 billion according to Thomson Reuters I/B/E/S.
In November, Qualcomm had forecast first-quarter revenue of $4.35 billion to $4.75 billion and first-quarter net earnings per share of 70 cents to 76 cents.
Qualcomm shares rose 5 percent to $62.58 in late trade after closing at $59.56 in the regular Nasdaq session.
(Reporting By Sinead Carew; Editing by Steve Orlofsky, Phil Berlowitz and David Gregorio)
LOS ANGELES (AP) ? Drug cartels have developed a number of money laundering schemes in recent years to turn dirty proceeds into clean cash.
Among them was working with a Los Angeles toy company that sold cuddly stuffed animals. Large amounts of cash were dropped off by couriers at Angel Toy Corp.'s downtown headquarters, broken down into smaller amounts and deposited into company accounts. The money was eventually funneled back to Colombia and into the hands of drug lords, authorities said.
On Tuesday, two Angel Toy co-owners are expected to be sentenced for their role in a case that highlights how cartels have attempted to avoid detection.
Federal prosecutors said the toy company served as a financial conduit for the drug cartels in a scheme commonly known as the black market peso exchange. The scam allows middlemen to handle transactions between drug dealers and others who want to buy U.S. dollars outside the legitimate banking system to avoid taxes and import fees.
More than $1.6 million was deposited into Angel Toy's bank accounts over a two-year period and each deposit was for less than $10,000 to avoid raising suspicion, court documents show.
The money was then used by a Colombian importer to purchase teddy bears and other stuffed animals. These toys were sent on to Colombia, where the importer sold them and gave the proceeds, in pesos, to the drug traffickers, authorities said.
Meichun Cheng Huang and Ling Yu pleaded guilty last year to one count of conspiracy to structure currency transactions and face up to 15 months in prison as part of an agreement with prosecutors.
The company also pleaded guilty to the same charge and will likely have to forfeit $1 million dollars and pay a $200,000 fine.
Prosecutors said that while Huang and Yu, who are sisters, haven't acknowledged knowing the money came from drug cartels, the scheme continued even after Angel Toy was audited in 2008.
"Even though the suspicious cash drops and egregious structuring scream of unlawful activity, business owners like Huang agree to 'look the other way' and make a substantial profit in the meantime," prosecutors wrote in court documents.
Both Huang and Yu spoke of their charitable work and devotion to their family in court documents but neither addressed if they were aware they worked at the behest of drug cartels.
"I am regretful for my failures, but I am determined to never again do anything that is not honorable," Huang said.Associated Press