Did bacteria spark evolution of multicellular life?

ScienceDaily (Oct. 23, 2012) ? Bacteria have a bad rap as agents of disease, but scientists are increasingly discovering their many benefits, such as maintaining a healthy gut.

A new study now suggests that bacteria may also have helped kick off one of the key events in evolution: the leap from one-celled organisms to many-celled organisms, a development that eventually led to all animals, including humans.

Published this month in the inaugural edition of the new online journal eLife, the study by University of California, Berkeley, and Harvard Medical School scientists involves choanoflagellates (aka "choanos"), the closest living relatives of animals. These microscopic, one-celled organisms sport a long tail or flagellum, tentacles for grabbing food and are members of the ocean's plankton community. As our closest living relative, choanos offer critical insights into the biology of their last common ancestor with animals, a unicellular or colonial organism that lived and died over 650 million years ago.

"Choanoflagellates evolved not long before the origin of animals and may help reveal how animals first evolved," said senior author Nicole King, UC Berkeley associate professor of molecular and cell biology.

Since first starting to study choanoflagellates as a post-doc, King has been trying to figure out why some choanoflagellates live their lives as single cells, while others form colonies. After years of dead ends, King and undergraduate researcher Richard Zuzow discovered accidentally that a previously unknown species of bacteria stimulates one choanoflagellate, Salpingoeca rosetta, to form colonies. Because bacteria were abundant in the oceans when animals first evolved, the finding that bacteria influence choano colony formation means it is plausible that bacteria also helped to stimulate multicellularity in the ancestors of animals.

"I would be surprised if bacteria did not influence animal origins, since most animals rely on signals from bacteria for some part of their biology," King said. "The interaction between bacteria and choanos that we discovered is interesting for evolutionary reasons, for understanding how bacteria interact with other organisms in the oceans, and potentially for discovering mechanisms by which our commensal bacteria are signaling to us."

No one is sure why choanoflagellates form colonies, said one of the study's lead authors, UC Berkeley post-doctoral fellow Rosanna Alegado. It may be an effective way of exploiting an abundant food source: instead of individual choanoflagellates rocketing around in search of bacteria to eat, they can form an efficient bacteria-eating "Death Star" that sits in the middle of its food source and chows down.

Whatever the reasons, colonies of unicellular organisms may have led the way to more permanent multicellular conglomerations, and eventually organisms composed of different cell types specialized for specific functions.

Sequencing the choanoflagellate genome

King's 12-year search for the trigger of choanoflagellate colony development was reignited in 2005 when she started to prime cultures of the choanoflagellate S. rosetta for a genome sequencing project. The sequencing of another choanoflagellate, the one-celled Monosiga brevicollis, gave some clues into animal origins, but she needed to compare its genome to that of a colony-forming choanoflagellate.

Surprisingly, when Zuzow tried to isolate the colony-forming choanoflagellate by adding antibiotics to the culture dish to kill off residual bacteria, strange things happened, said King.

"When he treated the culture with one cocktail of antibiotics, he saw a bloom of rosette colony formation," she said, referring to the rose petal-shaped colonies that were floating in the culture media. "When he treated with a different cocktail of antibiotics, that got rid of colony formation altogether."

That "rather mundane but serendipitous observation" led Zuzow and Alegado to investigate further and discover that only one specific bacterial species in the culture was stimulating colony formation. When other bacteria outnumbered it, or when antibiotics wiped it out, colony formation stopped. Alegado identified the colony-inducing bacteria as the new species, Algoriphagus machipongonensis. While she found that other bacteria in the Algoriphagus genus can also stimulate colony formation, other bacteria like E. coli, common in the human gut, cannot.

Working with Jon Clardy of Harvard Medical School, a natural products chemist, the two labs identified a molecule -- a fatty acid combined with a lipid that they called RIF-1 -- that sits on the surface of bacteria and is the colony development cue produced by the bacteria.

"This molecule may be betraying the presence of bacteria," Alegado said. "Bacteria just sit around blebbing off little membrane bubbles, and if one of them has this molecule, the choanoflagellates all of a sudden say, 'Aha, there are some bacteria around here.'"

The signal sets off a predetermined program in the choanoflagellate that leads to cell division and the development of rosettes, she said. The molecule RIF-1 is remarkably potent; choanos detect and respond to it at densities that are about one billionth that of the lowest concentration of sugar that humans can taste in water.

"We are investigating this molecule from many sides. How and why do bacteria make it? How do choanoflagellates respond to it, and why?" King said. She and her team also are analyzing the genome of the colony-forming choanoflagellate and the colony-inducing bacteria for clues to their interaction.

King hopes that this unexpected signaling between choanoflagellates and bacteria can yield insights into other ways in which bacteria influence biology, particularly the biology of the gut.

Coauthors with King, Alegado and Clardy are Zuzow, now a graduate student at Stanford University; Laura Brown, now a faculty member at Indiana University; Shugeng Cao and Renee Dermenjian of Harvard Medical School; and Stephen Fairclough of UC Berkeley. Dermenjian is now at Merck.

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The above story is reprinted from materials provided by University of California - Berkeley. The original article was written by Robert Sanders.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Rosanna A Alegado, Laura W Brown, Shugeng Cao, Renee K Dermenjian, Richard Zuzow, Stephen R Fairclough, Jon Clardy, Nicole King. A bacterial sulfonolipid triggers multicellular development in the closest living relatives of animals. eLife, 2012; 1 DOI: 10.7554/eLife.00013

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.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/top_environment/~3/jc083uSCCwo/121024101758.htm

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Timing is everything: Hormone use may reduce or increase Alzheimer's disease risk in women

ScienceDaily (Oct. 24, 2012) ? A new study suggests that women who begin taking hormone therapy within five years of menopause may reduce their risk of developing Alzheimer's disease. The research is published in the October 24, 2012, online issue of Neurology?, the medical journal of the American Academy of Neurology.

"This has been an area of debate because observational studies have shown a reduced risk of Alzheimer's disease with hormone therapy use, while a randomized controlled trial showed an increased risk. Our results suggest that there may be a critical window near menopause where hormone therapy may possibly be beneficial," said study author Peter P. Zandi, PhD, with Johns Hopkins University in Baltimore. "On the other hand, if started later in life, hormone therapy could be associated with an increased risk of developing Alzheimer's disease."

For the study, researchers followed 1,768 women ages 65 and older for 11 years. The women provided a history of their hormone therapy use and the date at which menopause began. A total of 1,105 women had used hormone therapy, consisting of estrogen alone or in combination with a progestin. During the study, 176 women developed Alzheimer's disease dementia, including 87 of the 1,105 women who had taken hormone therapy compared to 89 of the 663 others.

The study found that women who began hormone therapy within five years of menopause had a 30-percent lower risk of Alzheimer's dementia than those who had not used hormone therapy. The risk was unchanged among other hormone users who had begun treatment more than five years after menopause, but a higher risk of dementia was observed among women who had started a combined therapy of estrogen and progestin when they were at least 65 years old.

"While this well-designed study supports the possibility that short-term hormone use may reduce the risk of Alzheimer's disease, more research is needed before we can make new clinical recommendations for women and their use of hormone therapy," said Victor Henderson, MD, MS, with Stanford University in Stanford, Calif., and a Fellow of the American Academy of Neurology, who wrote an accompanying editorial.

The study was supported by the National Institute on Aging.

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The above story is reprinted from materials provided by American Academy of Neurology.

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Journal Reference:

1. Huibo Shao, John C.S. Breitner, Rachel A. Whitmer, Junmin Wang, Kathleen Hayden, Heidi Wengreen, Chris Corcoran, JoAnn Tschanz, Maria Norton, Ron Munger, Kathleen Welsh-Bohmer, and Peter P. Zandi. Hormone therapy and Alzheimer disease dementia: New findings from the Cache County Study WNL. Neurology, October 24, 2012 DOI: 10.1212/WNL.0b013e318271f823

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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/most_popular/~3/paDFrtUGZ70/121024164717.htm

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Oxygen's ups and downs in early atmosphere and ocean

ScienceDaily (Oct. 23, 2012) ? Most researchers imagine the initial oxygenation of the ocean and atmosphere to have been something like a staircase, but with steps only going up. The first step, so the story goes, occurred around 2.4 billion years ago, and this, the so-called Great Oxidation Event, has obvious implications for the origins and evolution of the first forms of eukaryotic life. The second big step in this assumed irreversible rise occurred almost two billion years later, coinciding with the first appearances and earliest diversification of animals.

Now a team led by geochemists at the University of California, Riverside challenges the simple notion of an up-only trend for early oxygen and provides the first compelling direct evidence for a major drop in oxygen after the first rise.

"Our group is among a subset of scientists who imagine that oxygen, once it began to accumulate in the ocean-atmosphere system, may have ultimately risen to very high levels about 2.3-2.2 billion years ago, perhaps even to concentrations close to what we see today," said Timothy Lyons, a professor of biogeochemistry and the principal investigator of the project. "But unlike the posited irreversible rise favored by many, our new data point convincingly to an equally impressive, and still not well understood, fall in oxygen about 200 million years later."

According to Lyons, this drop in oxygen may have ushered in more than a billion years that were marked by a return to low-oxygen concentrations at Earth's surface, including the likelihood of an oxygen-free deep ocean.

"It is this condition that may have set the environmental stage and ultimately the clock for the advance of eukaryotic organisms and eventually animals," he said.

Study results appear online this week in the Proceedings of the National Academy of Sciences.

"The time window between 2.3 and 2.1 billion years ago is famous for the largest and longest-lived positive carbon isotope excursion in Earth history," said Noah Planavsky, a recent Ph.D. graduate from UC Riverside, current postdoctoral fellow at Caltech, and first author of the research paper.

He explained that carbon isotopes are fractionated during photosynthesis. When organic matter is buried, oxygen is released and rises in the biosphere. The burial of organic matter is tracked by the positive or heavy isotopic composition of carbon in the ocean.

"Some workers have attributed the carbon isotope excursion to something other than organic burial and associated release of oxygen," Planavsky said. "We studied the sulfur isotope composition of the same rocks used for the carbon isotope analyses -- from Canada, South Africa, the U.S., and Zimbabwe -- and demonstrated convincingly that the organic burial model is the best answer."

The researchers' sulfur data point to high sulfate concentrations in the ocean, which, like today, is a classic fingerprint of high oxygen levels in the ocean and atmosphere. Sulfate, the second most abundant negatively charged ion in the ocean today, remains high when the mineral pyrite oxidizes easily on the continents and is buried in relatively small amounts in the oxygen-rich ocean.

"What is equally impressive is that the rise in oxygen was followed by a dramatic fall in sulfate and therefore oxygen," Lyons said. "Why the rise and fall occurred and how that impacted the billion years or more of ocean chemistry that followed and the life within that ocean are hot topics of research."

The research team is thrilled to have found strong chemical evidence for oxygen variability on the early Earth.

"The idea that oxygen levels at Earth's surface went up and down must be vital in any effort to understand the links between environmental and biological evolution on broad, geologic time scales," Planavsky said.

He and Lyons were joined in the study by Andrey Bekker at the University of Manitoba, Axel Hofmann at the University of Johannesburg and Jeremy Owens at UCR.

The NASA Exobiology Program supported this research. A National Science Foundation (NSF) Graduate Research Fellowship and a postdoctoral fellowship from the NSF Division of Earth Sciences covered Planavsky's salary.

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The above story is reprinted from materials provided by University of California - Riverside. The original article was written by Iqbal Pittalwala.

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Journal Reference:

1. N. J. Planavsky, A. Bekker, A. Hofmann, J. D. Owens, T. W. Lyons. Sulfur record of rising and falling marine oxygen and sulfate levels during the Lomagundi event. Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1120387109

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Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/~3/CJXMFclzYEk/121023134812.htm

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Zynga Reports Third Quarter Revenue Of $317M, Shares Pop 12.7% In After-Hours On Casino Push

Zynga said it saw third quarter revenue of $317 million, which was slightly above the lower range of $300 million to $305 million the company said it would see earlier this month.?Bookings came in at $256 million, up 11 percent year-over-year.?The company saw a loss of 7 cents per share, and its non-GAAP earnings, which exclude one-off share based compensation costs, were 0 cents per share. Because the revenues came in slightly ahead of the company's earlier forecasts, the company's shares popped 10 percent in after-hours trading to $2.36 from today's close of $2.12.

Source: http://feedproxy.google.com/~r/Techcrunch/~3/rT2lW7mSs4c/

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NY Times public editor asks if incoming CEO fit to serve

NEW YORK (Reuters) - The New York Times public editor has questioned whether incoming chief executive Mark Thompson, the former head of the BBC, is fit to serve as the company's top official as a scandal shakes Britain's most prestigious broadcaster.

One Wall Street analyst called for the New York Times Co, which publishes its namesake newspaper and the Boston Globe, to delay Thompson taking over the company. That added more pressure on executives to address the matter on the company's earnings conference call on Thursday.

The BBC has been damaged by the scandal involving one of its most famous entertainers, the late Jimmy Savile, who is accused of sexually abusing hundreds of women and girls over the course of six decades. Savile, the eccentric host of the "Top of the Pops" music show, died last year at the age of 84.

Thompson held the top job as director general at the BBC from 2004 until September and also held the title of editor-in-chief, according to a description of the Director General's duties on the BBC website.

"How likely is it that (Thompson) knew nothing?" New York Times public editor Margaret Sullivan wrote in a blog post on Tuesday.

"His integrity and decision-making are bound to affect The Times and its journalism -- profoundly. It's worth considering now whether he is the right person for the job, given this turn of events."

A New York Times spokesman declined to comment.

No evidence has emerged in police and parliamentary investigations that shows Thompson knew about the decision to pull the Newsnight program or about Savile's alleged behaviour.

Thompson did not respond immediately to an email seeking comment about the public editor's column.

The allegations enveloping the British broadcaster hinge partly on the BBC's decision last year to shelve a show at its flagship "Newsnight" program investigating Savile. Rival broadcaster ITV aired a bombshell report this month about Savile and the claims against him, which had been rumoured for years.

Last week, Thompson said in a statement, "I was not notified or briefed about the Newsnight investigation, nor was I involved in any way in the decision not to complete and air the investigation.

In her post, Sullivan commended the paper for "reporting this story regularly".

As public editor and a representative of readers, Sullivan writes about issues affecting the newspaper independent from News York Times management, including chairman and publisher Arthur Sulzberger Jr. and executive editor Jill Abramson.

Since stepping into the role in September, she has already made waves including a post that criticized the paper's decision not to publish on the front page a story about a congressional hearing into attacks on a U.S. consulate in Benghazi, Libya, last month in which four Americans were killed.

A representative from Sullivan's office said she declined to comment further on her blog about Thompson. An email sent to Sulzberger seeking comment was not returned immediately.

Sullivan's post on Thompson follows New York Times former executive editor Bill Keller, who wrote a column last week drawing a parallel between Savile and Penn State football coach Jerry Sandusky, who was recently sentenced to what amounts to life imprisonment for molesting children.

The New York Times tapped Thompson in August as CEO, a role that had been vacant eight months after the company ousted its former CEO Janet Robinson last year.

Thompson is expected to start with the Times on November 12. A New York Times spokesman told the paper on Tuesday, "We believe his experience and accomplishments make him the ideal person to take the helm of the Times Company as we focus on growing our businesses through digital and global expansion."

Like all Times executives, Thompson is an "at will" employee meaning he can leave or the company can terminate his employment at any time.

He stands to make $6 million next year including his base salary, bonuses based on targets and $3 million in performance-based options.

The unfolding Savile scandal has also caught the attention of some analysts in the United States.

"The New York Times should delay (Thompson's) start date until there is more clarity," said Doug Arthur, an analyst with Evercore Partners who follows the New York Times.

"It seems to me he will have to attend a hearing in the UK parliament. That is going to be a distraction. It's unfortunate. It's an unexpected complication."

In a hearing with British lawmakers on Tuesday, BBC Director General George Entwistle denied that the BBC helped cover up allegations that Savile preyed on women.

Thompson said the Newsnight investigation was mentioned to him by a journalist at a party last year, but he was later told it was not going ahead for journalistic reasons.

"I was never formally notified about the Newsnight investigation and was not briefed about the allegations they were examining and to what extent, if at all, those allegations related to Savile's work at the BBC," he said in a letter to a British lawmaker on Tuesday.

Thompson added he would be happy to appear in front of the parliamentary committee or any other inquiry in future.

In an interview with the New York Times on Tuesday, Thompson restated that he was not aware of the program until after it was cancelled.

"I talked to senior management in BBC News and reported the conversation I had at the party and asked was there a problem," Thompson told the paper.

"I did not impede or stop the Newsnight investigation, nor have I done anything else that could be construed as untoward or unreasonable."

Newsnight's editor, Peter Rippon, stepped aside on Monday after the BBC said his explanation for shelving the story had been "inaccurate or incomplete".

(Reporting By Jennifer Saba; Editing by Edward Tobin, Paul Tait, Jean Yoon, Theodore d'Afflisio, Andrew Hay)

Source: http://news.yahoo.com/ny-times-public-editor-calls-incoming-ceo-thompson-055245548--finance.html

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Forbes Presents Collection of Estate Planning Articles - The Wiewel ...

With all the noise these days about taxing the rich and the future of the federal estate tax, the message that ordinary folks also need to plan, to protect themselves and their families, gets drowned out.

Did you know we just passed National Estate Planning Awareness Week (Oct. 15-21)? Don?t worry if you missed it, estate planning is a continuous endeavor and one that is never out of season.

While proper estate planning is no Do-It-Yourself project and competent legal counsel should be retained, there is plenty of literature available to help you learn the basics of estate planning and beyond. Leave it to Forbes to compile ?The Forbes Guide To Estate Planning? from its storehouse of past estate planning articles. Of course, these 40 some articles give only the Forbes perspective, but it?s a quick glimpse at the panoply of topics and worth a read.

If you still need information on estate planning topics and strategies, contact your legal and financial counselors in order to gain knowledge about protecting your family and your assets.

Reference: Forbes (October 14, 2012) ?The Forbes Guide To Estate Planning?

Source: http://blog.texastrustlaw.com/2012/10/forbes-presents-collection-of-estate-planning-articles.html

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Jennifer Lopez Flaunts Her Abs in London

10/22/2012 at 04:30 PM EDT

They say if you've got it, flaunt it ? and Jennifer Lopez did just that.

The mother of twins exposed her enviable abs while out and about in London on Monday with boyfriend Casper Smart.

Clad in a tight-fitting cropped black top with black pants and a long, gray coat, the physically fit star, 43, strolled alongside her man, who was also dressed in a similar color scheme.

Lopez worked hard with trainer Tracy Anderson on a custom routine that targeted the area from the singer's abs to her hips.

"We don't want her natural beauty to go out of balance," Anderson told PEOPLE over the summer. "[Overly] ripped abs would ruin her look."

In the end, Lopez "loves the results," according to Anderson.

Source: http://feeds.people.com/~r/people/headlines/~3/8Y0DZilyALs/0,,20641361,00.html

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