Aparna Sherlekar, Gayatri Mundhe, Prachi Richa, Bipasha Dey, Swati Sharma, and Richa Rikhy

Branched actin networks driven by Arp2/3 collaborate with actomyosin filaments in processes such as cell migration. The syncytial Drosophila blastoderm embryo also shows expansion of apical caps by Arp2/3 driven actin polymerization in interphase and buckling at contact edges by MyosinII to form furrows in metaphase. Here we study the role of Syndapin (Synd), an F-BAR domain containing protein in apical cap remodelling prior to furrow extension. synd depletion showed larger apical caps. STED super-resolution and TIRF microscopy showed long apical actin protrusions in caps in interphase and short protrusions in metaphase in control embryos. synd depletion led to sustained long protrusions even in metaphase. Loss of Arp2/3 function in synd mutants partly reverted defects in apical cap expansion and protrusion remodelling. MyosinII levels were decreased in synd mutants and MyosinII mutant embryos have been previously reported to have expanded caps. We propose that Syndapin function limits branching activity during cap expansion and affects MyosinII distribution in order to shift actin remodeling from apical cap expansion to favor lateral furrow extension.

Kelly L. Dunlevy, Valentina Medvedeva, Jade E. Wilson, Mohammed Hoque, Trinity Pellegrin, Adam Maynard, Madison M. Kremp, Jason S. Wasserman, Andrey Poleshko, and Richard A. Katz

A large fraction of epigenetically silent heterochromatin is anchored to the nuclear periphery via "tethering proteins" that function to bridge heterochromatin and the nuclear membrane or nuclear lamina. We identified previously a human tethering protein, PRR14, that binds heterochromatin through an N-terminal domain, but the mechanism and regulation of nuclear lamina association remained to be investigated. Here we identify an evolutionarily conserved PRR14 nuclear lamina binding domain (LBD) that is both necessary and sufficient for positioning of PRR14 at the nuclear lamina. We also show that PRR14 associates dynamically with the nuclear lamina, and provide evidence that such dynamics are regulated through phosphorylation-dephosphorylation of the LBD. Furthermore, we identified a PP2A phosphatase recognition motif within the evolutionarily conserved PRR14 C-terminal Tantalus domain. Disruption of this motif affected PRR14 localization to the nuclear lamina. The overall findings demonstrate a heterochromatin anchoring mechanism whereby the PRR14 tether simultaneously binds heterochromatin and the nuclear lamina through two separable, modular domains. The findings also describe an optimal PRR14 LBD fragment that could be used for efficient targeting of fusion proteins to the nuclear lamina.

More than 500 carats of rough diamonds were recently donated to the Department of Mineral Sciences of the Smithsonian’s Natural History Museum by Jewlers Mutual Insurance Co. of Neenah, Wis.

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The National Museum of Natural History will permanently display the Dom Pedro Aquamarine, which is the largest single piece of cut-gem aquamarine in the world, beginning Dec. 6.

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Dr. Mary Hagedorn, a marine biologist at the Smithsonian Institution, talks about her research to understand and conserve our oceans' corals.

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Dr. Mary Hagedorn, a marine biologist at the Smithsonian Institution, talks about her research to understand and conserve our oceans' corals. To meet more scientists, visit https://insider.si.edu.

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Smithsonian Scientist Helen James dives into dormant Hawaiian volcanoes to find bird fossils. Her work to identify these species (some new species, some extinct) helps us learn about the past--specifically, how humans might have caused the extinction of certain bird species.

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When birds and planes collide: Carla Dove, a forensic ornithologist at the Smithsonian's National Museum of Natural History, talks about the work of the Smithsonian's Feather Identification Lab and its role in improving aviation safety.

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The post How do paleontologists identify dinosaur teeth? Smithsonian Curator Matthew Carrano identifies Cretaceous dinosaur teeth from the Washington D.C. area. appeared first on Smithsonian Insider.

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The post Kepler 11: A Six-Planet Sonata by Alex Parker, postdoctoral researcher at the Harvard–Smithsonian Center for Astrophysics appeared first on Smithsonian Insider.

Ted Schultz, research entomologist at Smithsonian’s National Museum of Natural History, describes how ants use their incredible sense of smell along with their ability to […]

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The National Museum of Natural History in Washington, D.C., has closed its Dinosaur Hall for a five-year renovation. But before the overhaul can begin, the […]

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Lion start vocalizing as soon as they’re born. But when and why do they start to roar? We ask caretakers at Smithsonian’s National Zoo.

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Time-lapse captured at the Hirshhorn Museum of Yayoi Kusama’s The Obliteration Room, on view in “Yayoi Kusama: Infinity Mirrors.” In Yayoi Kusama’s “The Obliteration Room,” […]

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More than 154 million treasures fill the Smithsonian’s vaults, but where public view ends, Sidedoor begins. With the help of biologists, artists, historians, archaeologists, zookeepers […]

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  Frances Glessner Lee created dollhouses with dead dolls. Her creations are now on exhibit at the Renwick Gallery of the Smithsonian American Art Museum.

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Tweaks in muscle and wing form give different hummingbird species varying levels of agility. The deft turns of hummingbirds in flight, as shown in a […]

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When you look at fast growing private companies in the U.S., you need look no further than a small city next to Los Angeles International Airport.

Steve Julian: Business analyst Mark Lacter, tell us about the company that's based in El Segundo.

Mark Lacter: It's called Fuhu, Steve - that might ring a bell with some parents because Fuhu is the maker of the Nabi.  The Nabi is an Android tablet for kids, and it's a very cool device that mimics a lot of the capabilities of regular tablet, including the ability to play games and get onto the Web (with controls that parents are able to set up).  Last year, they sold 1.2 million Nabis, and that helped push the El Segundo company to the very top of Inc. magazine's list of fastest-growing businesses.  That's number one on a list of 5,000 companies, with a three-year growth rate of 42,148 percent.  Or, to put it another way, company revenue was $279,000 in 2009; it was almost $118 million in 2012.  Now, by the standards of an Apple or a Samsung, those are still not huge numbers -

Julian: - and maybe that explains why there's been relatively little media coverage of this company.

Lacter: It might also explain why local tech companies in general get short shrift.  Many of them are quite successful, but they're often on the small side, and they're also privately held as opposed to publicly-traded on a stock exchange.  That's one big difference from Silicon Valley, which has so many huge public corporations: Apple, Intel, HP.  L.A. County has only six Fortune 500 companies, and not a single one devoted solely to technology.  In Silicon Valley, there are 22 in the Fortune 500.

Julian: And yet, the L.A. economy has more than held its own without those large corporations.

Lacter: Matter of fact, the accounting firm PriceWaterhouse studied more than two dozen cities around the world to determine where it was easiest to do business (that's based on factors like access to labor), and what they found - somewhat surprisingly - was that L.A. ranked ahead of both San Francisco and Tokyo.  And, you can see evidence of that with the increase in venture capital money coming into all parts of L.A.  Now, it's important to keep an eye on all these up-and-coming companies because these businesses are helping generate higher-wage jobs.  And, for an area with a still-high unemployment rate - still over 10 percent in some places -- that's a big deal.

Julian: Speaking of companies, does anyone want to buy the L.A. Times?

Lacter: The answer is yes - most recently, the controlling owner of the Dodgers, Mark Walter, said he was interested in both the Times and the Chicago Tribune (though there's no way to know whether there are actual discussions taking place).  You also have several local groups, including one that involves billionaire Eli Broad, that have been interested to one degree or another.  But what was thought would be a fairly straightforward auction process has turned enormously complicated.  It's now to the point where the Tribune board has decided spin off the papers into a separate business, and that process will take until next year to complete and could preclude any sales for quite some time after that.

Julian: So, it's Limbo-land for the Times for who knows how long.

Lacter: Steve, it's not that Tribune really wants to keep the newspapers.  But, selling them off presents huge tax implications.  Also, there are assets that the potential buyers thought would be part of the package - assets that include real estate - that Tribune wants to hold onto.  So, what's left to sell are just the newspapers themselves, and frankly, they're among the least valuable properties.

Julian: Now, last week came word that the billionaire Koch brothers, who were believed to be interested in the Tribune properties, decided not to pursue a deal...

Lacter: ...that's right, they don't consider the Times or the other dailies to be economically viable.  You might recall a bit of an outcry over the prospect of having the Kochs, who are staunch conservatives, becoming the owners of these papers.  So, they're out of the picture.  But for the L.A. Times, it's really the worst of all worlds: no new owner and no vision for recasting the paper, at least in the near term.

Mark Lacter writes for Los Angeles Magazine and pens the business blog at LA Observed.com.

This content is from Southern California Public Radio. View the original story at SCPR.org.

The partial federal government shutdown is one week old, but economists are still saying that its impact in Southern California and elsewhere will be limited.

Susanne Whatley: Business analyst Mark Lacter, why is that?

Mark Lacter: If you look back on the history of these things, Susanne, you see that the disputes are resolved before too much damage gets done.  As for Southern California, I notice that KPCC's Alice Walton was asking around over the weekend about the shutdown, and most folks gave it a shrug.  The regional economy is just too diversified - and not especially tied to federal employment.  You have about 46,000 federal workers employed in L.A. County in one capacity or another - that's out of a workforce of nearly 5 million.  And, now it appears as if the federal employees who have been furloughed are going to receive their back wages whenever the shutdown finally ends.

Whatley: That still might make things dicey when it comes time to pay the monthly mortgage...

Lacter: ...but at least money will be available before most folks run into serious liquidity issues.  That's what the shutdown really comes down to - inconvenience rather than dislocation.  And, you see this with the various government services affected: the E-Verify website is down - that lets business owners know whether the people they're wanting to hire can work legally in the U.S., which obviously is important.  The Small Business Administration has stopped processing loan applications, and the Federal Housing Administration is reporting delays in its loan processing, which could mean a home buyer might not complete his or her paperwork all that quickly.

Whatley: But, what if this were to go on for months?

Lacter: Well, then it would create problems, but nobody really thinks that's going to happen.  The real issue, not just nationally and regionally - but globally - is the refusal by Congress to raise the debt ceiling.  The deadline is a week from Thursday, and - of course - there's been all sorts of debate about what this would mean for the economy.

Whatley: All right, so what would this mean for the economy?

Lacter: Well, no one knows exactly.  But, then again, no one knows exactly what would happen if you fell out of a airplane without a parachute.  I just wouldn't want to test it out.  And, of course, let's keep in mind that these are manufactured crises - not reflective of anything that's going on with the real economy.  It's certainly not reflective of anything that's going on in L.A., which saw a big jump in payroll jobs for 2012 - actually it was the sharpest increase since 2005, and nearly double the national rate (that's despite an unemployment rate that remains very high in certain parts of Los Angeles).

Whatley: What about some of the big locally based companies?

Lacter: Well, if your company is publicly traded, there's a good chance your shares took a dip these past few days.  Going back to September 18, the Dow has lost almost 700 points, which - percentage-wise - is not very much, but it is reflective of how uneasy Wall Street has become.  Public companies based in the L.A. area are taking it on the chin - Disney, Amgen, Mattel, DirecTV - their stock prices are all down going back to the middle of September.

Whatley: Even so, hasn't this been a good year for the stock market?

Lacter: It has - those local companies are up anywhere from 13 percent 30 percent year to date, and the Dow is up 14 percent year to date.  Of course, the stock price of a company doesn't always match the amount of money it makes, and this year, even before worries about the debt ceiling, the numbers haven't been as good as they should be at this stage of a recovery.  And, that's why there's particular concern about next week.  You do have to wonder whether a default could have ripple effects involving trade, consumer spending, the dollar - who knows what?  Now, it's still a pretty good bet that saner heads will prevail, although there are no guarantees - and again, if worse came to worse, do you really want to be jumping out of that plane?  Guess we'll find out.

Mark Lacter writes for Los Angeles Magazine and pens the business blog at LA Observed.com.

This content is from Southern California Public Radio. View the original story at SCPR.org.

The state's online registration for Covered California has been up for a couple of weeks, and reaction has been mixed.

Steve Julian: Business analyst, Mark Lacter, what's your take on how well Californians are getting into the Affordable Care Act?

Mark Lacter: It's hard to get a good read, Steve, because it's hard to measure the success of what is really a new marketplace.  If you're basing it on the number of unique visitors coming to the Covered California website, well, then the program clearly has attracted lots of interest - they had almost a million visitors during the first week of eligibility.  But, maybe a better measure would be the number of people whose applications actually have been received by the insurance companies that are going to handle the claims.  If that's your measuring stick, then the numbers have been far smaller so far.  Now, it's worth pointing out that California - and particularly L.A. County - have a higher percentage of households without insurance than other parts of the nation, and so you'd expect there to be lots of interest.

Julian: So the question, then, is how many folks turn into actual policyholders paying actual premiums each month.

Lacter: The truth is nobody knows, which is why state officials want to sign up as many people as possible in the early going when the program is getting so much attention.  This is especially true for younger and healthier people who are needed to help offset the cost of caring for older and sicker people.

Julian: And, that's also why any computer glitch can be such a headache...

Lacter: That's right.  Covered California did run into problems in the early going, but everybody agrees that things are going much better than the federal website, which is the default site used by folks in states that don't have their own program to oversee the health care laws.  That federal site has been an utter disaster.  So, by comparison, California is ahead of the game.

Julian: It's a work in progress, even here.

Lacter: Very much so.  The California website still doesn't have a way for enrollees to find out which doctors and hospitals are included in each health plan.  And, that's a big deal because  insurance companies are limiting the options available as a way of keeping premiums low.  So, it's possible that the doctor you had been using for your individual insurance plan will not be on the list of doctors that can be used for one of the cheaper plans.  Of course, for someone who doesn't have any health coverage, none of that is likely to matter.

Julian: And then, there's the continued threat of a U.S. default...

Lacter: You know, Steve, this is like watching the beginning of a bad traffic accident in slow motion - and we're all pretty helpless to do anything about it.  And, so are the financial markets, which are moving back and forth not based on what's going on with the economy or with any industry, but on the latest press conference out of Washington.  One thing we do know is that if the nation does go into quote-unquote default - and we're not even sure what that might mean - but if Wall Street and somehow declares this a major crisis, it's going to be bad.

Julian: Who gets hit?

Lacter: It'll impact anyone who has a retirement account, any business wanting to borrow money, and potentially it's going to impact the budgeting of the state.  You know, one of the things we were reminded of during the Great Recession was how reliant California has been on higher-income individuals who make a lot of their money through the stock market and other investments.  So, when those folks do well - as they have been over the last year - the state coffers will do well.  And when they don't, as was the case in 2008 and 2009, the state takes a huge hit because there's not enough tax dollars coming in.  Gov. Brown and others have tried to lessen the reliance on those top tiers - so far without success.

Julian: And the state's budget situation is so much better than it was a year or two ago.

Lacter: That's the real pity.  And, even if the House and Senate reach a temporary agreement on the debt ceiling, it's just a matter of weeks or months before another deadline crops up - and more uncertainty for the financial markets.  I guess Chick Hearn would have called this nervous time.

Mark Lacter writes for Los Angeles Magazine and pens the business blog at LA Observed.com.

This content is from Southern California Public Radio. View the original story at SCPR.org.