The fossil teeth of a 15- to 18-million-year-old three-toed browsing horse, Anchitherium clarencei, were recently discovered by scientists from the Smithsonian Tropical Research Institute and the […]

The post Fossil teeth of 15-million-year-old browsing horse found in Panama Canal excavations. appeared first on Smithsonian Insider.

Already under siege from overfishing, disease and poor water quality, the oyster population in the Chesapeake Bay today stands at 2 percent of what it was in colonial times. Now, new data show that rising acidity in the Bay will have a negative impact on oyster shells.

The post Rising acidification of estuary waters spells trouble for Chesapeake Bay oysters appeared first on Smithsonian Insider.

The newfound world, GJ1214b, is about 6.5 times as massive as the Earth. Its host star, GJ1214, is a small, red type M star about one-fifth the size of the Sun. GJ1214b orbits its star once every 38 hours at a distance of only 1.3 million miles. Astronomers estimate the planet's temperature to be about 400 degrees Fahrenheit. Although warm as an oven, it is still cooler than any other known transiting planet because it orbits a very dim star.

The post Astronomers Find Super-Earth Using Amateur, Off-the-Shelf Technology appeared first on Smithsonian Insider.

Should global warming cause sea levels to rise as predicted in coming decades, thousands of archaeological sites in coastal areas around the world will be lost to erosion. With no hope of saving all of these sites, three archaeologists—Leslie Reeder of Southern Methodist University, Jon Erlandson of the University of Oregon and Torben Rick from the Smithsonian's National Museum of Natural History—have issued a call to action for scientists to assess the sites most at risk around the world.

The post Scientists issue call to action for archaeological sites threatened by rising seas, urban development appeared first on Smithsonian Insider.

A recent experiment by scientists at the Smithsonian Tropical Research Institute in Panama has revealed just how rising atmospheric carbon dioxide will deliver a one-two […]

The post Rising ocean temperatures and acidity may deliver deadly one-two punch to the world’s corals appeared first on Smithsonian Insider.

A new species of Brazilian leaf beetle named Cachiporra extremaglobosa, (which translated means the “extremely globular billy club leaf beetle,”) was recently discovered by scientists at the Smithsonian’s National Museum of Natural History.

The post “Billy club” leaf beetle has been hiding in Smithsonian collections since 1959 appeared first on Smithsonian Insider.

The Smithsonian’s National Museum of the American Indian is hosting a series of public satellite broadcasts featuring a multinational team of researchers, engineers and archaeologists who are working in Peru on the origins and engineering of the Inka Road of South America.

The post American Indian Museum to host public broadcasts focusing on the Inka Road appeared first on Smithsonian Insider.

As a coastal archaeologist and expert in prehistoric and historic settlement sites in the Chesapeake Bay region, Darrin Lowery of the Smithsonian’s National Museum of Natural History and University of Deleware, is carefully watching the effects of coastal erosion and rising sea levels on coastal archaeological sites.

The post Rising seas, development are altering prehistoric artifacts in the Chesapeake’s tidal zone appeared first on Smithsonian Insider.

The newly reported reconstruction of Amazonian prehistory by a Smithsonian scientist, Dolores R. Piperno, and her colleagues suggests that large areas of western Amazonia were sparsely inhabited.

The post Report paints a new picture of early human impact on the Amazon River Basin appeared first on Smithsonian Insider.

Forget the deep forest, “today the highest densities of deer in the state of Virginia are in suburbia,” says William McShea, ecologist and research scientist at the Smithsonian’s Conservation Biology Institute in Front Royal, Va.

The post Browsing suburbia: Virginia’s parceled-up farms and forests are ideal refuge for white-tailed deer appeared first on Smithsonian Insider.

For the first time since exoplanets, or planets around stars other than the sun, were discovered almost 20 years ago, X-ray observations have detected an […]

The post NASA’s Chandra sees eclipsing planet in X-rays for first time appeared first on Smithsonian Insider.

After years of sleuthing for clues about where and when pantherine felids (“big cats”) originated, a Smithsonian scientist and an international team of researchers are […]

The post Smithsonian scientist confirms missing link in big cat evolution appeared first on Smithsonian Insider.

It has all the hallmarks of a paleontological crime scene: a massive graveyard along a remote desert highway containing the fossil bones of at least […]

The post Algae assassin found responsible for whale mass grave in Chile appeared first on Smithsonian Insider.

National Museum of Natural History scientist Torsten Dikow discovered and named a new species of assassin fly, Burmapogon bruckschi, after studying the first two specimens […]

The post Ancient species of assassin fly discovered by Smithsonian scientist appeared first on Smithsonian Insider.

Save the Rhinos! Save the Elephants! Save the humans?! It seems strange to be connecting our own fate to that of wildlife but new research […]

The post Losing large mammals increases human risk from rodent-borne diseases appeared first on Smithsonian Insider.

Tasty and easy to find, the heath hen was a favorite dish of America’s colonial settlers. This beautiful little bird, however, was no match for […]

The post Urban landscapes becoming increasingly bird-unfriendly appeared first on Smithsonian Insider.

Investigators from Rock County, Wisconsin, are one step closer to solving the mystery surrounding the death of an unknown teenager thanks to Smithsonian scientists. Christine […]

The post Smithsonian/Wisconsin police narrow search in 20 year mystery appeared first on Smithsonian Insider.

Stealthy. Aggressive. Lethal. Assassin flies are predators that hunt and feed on other insects. They are the third most diverse group of flies, with more […]

The post Killer Insect profile: The Assassin Fly appeared first on Smithsonian Insider.

On September 14, 2015, the Laser Interferometer Gravitational-wave Observatory (LIGO) detected gravitational waves from the merger of two black holes 29 and 36 times the […]

The post Ligo’s Twin Black Holes Might Have Been Born Inside a Single Star appeared first on Smithsonian Insider.

“Think of a lion shrunk to the size of a mouse that needs to eat every 20 minutes or so.” That is a shrew, says […]

The post New Costa Rican shrew species named from a single specimen found 44 years ago appeared first on Smithsonian Insider.

One of Earth’s most evolutionarily unique species is also the world’s most trafficked mammal: pangolins, or “scaly anteaters.” A new study from the Smithsonian Conservation […]

The post Using genetics to help save world’s most trafficked mammal: the pangolin appeared first on Smithsonian Insider.

In the past 50 years, the amount of water in the open ocean with zero oxygen has increased more than fourfold. In coastal water bodies, […]

The post Earth’s oceans are losing their breath. Here’s the global scope appeared first on Smithsonian Insider.

Flying through the air? Check. Surviving snake bites? Check. One of the most adorable creatures on earth? Absolutely! Do you think you know everything about […]

The post This Squirrel Appreciation Day we have a few surprising squirrely facts for you appeared first on Smithsonian Insider.

Little to nothing is known about how and where a small European songbird called the bluethroat spends much of the year. Now, Smithsonian scientists have […]

The post Scientists track a mysterious songbird using tiny backpack locators appeared first on Smithsonian Insider.

Bipasha Dey and Richa Rikhy

Cell shape morphogenesis from spherical to polygonal occurs in epithelial cell formation in metazoan embryogenesis. In syncytial Drosophila embryos, the plasma membrane incompletely surrounds each nucleus and is organized as a polygonal epithelial-like array. Each cortical syncytial division cycle shows circular to polygonal plasma membrane transition along with furrow extension between adjacent nuclei from interphase to metaphase. In this study, we assess the relative contribution of DE-cadherin and Myosin II at the furrow for polygonal shape transition. We show that polygonality initiates during each cortical syncytial division cycle when the furrow extends from 4.75 to 5.75 µm. Polygon plasma membrane organization correlates with increased junctional tension, increased DE-cadherin and decreased Myosin II mobility. DE-cadherin regulates furrow length and polygonality. Decreased Myosin II activity allows for polygonality to occur at a lower length than controls. Increased Myosin II activity leads to loss of lateral furrow formation and complete disruption of polygonal shape transition. Our studies show that DE-cadherin-Myosin II balance regulates an optimal lateral membrane length during each syncytial cycle for polygonal shape transition.

Su Ming Sun, Amandine Batte, Mireille Tittel-Elmer, Sophie van der Horst, Tibor van Welsem, Gordon Bean, Trey Ideker, Fred van Leeuwen, and Haico van Attikum

Eukaryotic chromosomes are replicated in interphase and the two newly duplicated sister chromatids are held together by the cohesin complex and several cohesin auxiliary factors. Sister chromatid cohesion is essential for accurate chromosome segregation during mitosis, yet has also been implicated in other processes, including DNA damage repair, transcription and DNA replication. To assess how cohesin and associated factors functionally interconnect and coordinate with other cellular processes, we systematically mapped genetic interactions of 17 cohesin genes centered on quantitative growth measurements of >52,000 gene pairs in budding yeast. Integration of synthetic genetic interactions unveiled a cohesin functional map that constitutes 373 genetic interactions, revealing novel functional connections with post-replication repair, microtubule organization and protein folding. Accordingly, we show that the microtubule-associated protein Irc15 and the prefoldin complex members Gim3, Gim4 and Yke2 are new factors involved in sister chromatid cohesion. Our genetic interaction map thus provides a unique resource for further identification and functional interrogation of cohesin proteins. Since mutations in cohesin proteins have been associated with cohesinopathies and cancer, it may also identify cohesin interactions relevant in disease etiology.

Tara L. Mastro, Vishnu P. Tripathi, and Susan L. Forsburg

Translesion synthesis polymerases (TLSPs) are non-essential error-prone enzymes that ensure cell survival by facilitating DNA replication in the presence of DNA damage. In addition to their role in bypassing lesions, TLSPs have been implicated in meiotic double strand break repair in several systems. Here we examine the joint contribution of four TLS polymerases to meiotic progression in the fission yeast S. pombe. We observed the dramatic loss of spore viability in fission yeast lacking all four TLSPs which is accompanied by disruptions in chromosome segregation during meiosis I and II. Rec8 cohesin dynamics are altered in the absence of the TLSPs. These data suggest that the TLSPs contribute to multiple aspects of meiotic chromosome dynamics.

Karolina Losenkova, Mariachiara Zuccarini, Marika Karikoski, Juha Laurila, Detlev Boison, Sirpa Jalkanen, and Gennady G. Yegutkin

Extracellular adenosine mediates diverse anti-inflammatory, angiogenic and vasoactive effects and becomes an important therapeutic target for cancer, which has been translated into clinical trials. This study was designed to comprehensively assess adenosine metabolism in prostate and breast cancer cells. We identified cellular adenosine turnover as a complex cascade, comprised of (a) the ectoenzymatic breakdown of ATP via sequential nucleotide pyrophosphatase/phosphodiesterase-1, ecto-5’-nucleotidase/CD73 and adenosine deaminase reactions, and ATP re-synthesis through counteracting adenylate kinase and nucleoside diphosphokinase; (b) the uptake of nucleotide-derived adenosine via equilibrative nucleoside transporters; and (c) the intracellular adenosine phosphorylation into ATP by adenosine kinase and other nucleotide kinases. The exposure of cancer cells to 1% O₂ for 24 hours triggered ~2-fold up-regulation of CD73, without affecting nucleoside transporters, adenosine kinase activity and cellular ATP content. The ability of adenosine to inhibit the tumor-initiating potential of breast cancer cells via receptor-independent mechanism was confirmed in vivo using a xenograft mouse model. The existence of redundant pathways controlling extracellular and intracellular adenosine provides a sufficient justification for reexamination of the current concepts of cellular purine homeostasis and signaling in cancer.

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.

Ana Loncar, Sergio A. Rincon, Manuel Lera Ramirez, Anne Paoletti, and Phong T. Tran

To segregate the chromosomes faithfully during cell division, cells assemble a spindle that captures the kinetochores and pulls them towards opposite poles. Proper spindle function requires correct interplay between microtubule motors and non-motor proteins. Defects in spindle assembly or changes in spindle dynamics are associated with diseases like cancer or developmental disorders. Here we compared mitotic and meiotic spindles in fission yeast. We show that even though mitotic and meiotic spindles undergo the typical three phases of spindle elongation, they have distinct features. We found that the relative concentration of kinesin-14 Pkl1 is decreased in meiosis I compared to mitosis, while the concentration of kinesin-5 Cut7 remains constant. We identified the second kinesin-14 Klp2 and microtubule dynamics as factors necessary for proper meiotic spindle assembly. This work defines differences between mitotic and meiotic spindles in fission yeast, and provides prospect for future comparative studies.

Left to themselves, coastal wetlands can adapt to sea-level rise. But humans could be sabotaging some of their best defenses, according to a review paper […]

The post Wetlands sinking with human-built structures appeared first on Smithsonian Insider.

Cambridge, MA -Physicists are capitalizing on a direct connection between the largest cosmic structures and the smallest known objects to use the universe as a […]

The post Scientists are using the universe as a “cosmological collider” appeared first on Smithsonian Insider.

Structural investigations of amorphous and nanocrystalline phases forming in solution are historically challenging. Few methods are capable of in situ atomic structural analysis and rigorous control of the system. A mixed-flow reactor (MFR) is used for total X-ray scattering experiments to examine the short- and long-range structure of phases in situ with pair distribution function (PDF) analysis. The adaptable experimental setup enables data collection for a range of different system chemistries, initial supersaturations and residence times. The age of the sample during analysis is controlled by adjusting the flow rate. Faster rates allow for younger samples to be examined, but if flow is too fast not enough data are acquired to average out excess signal noise. Slower flow rates form older samples, but at very slow speeds particles settle and block flow, clogging the system. Proper background collection and subtraction is critical for data optimization. Overall, this MFR method is an ideal scheme for analyzing the in situ structures of phases that form during crystal growth in solution. As a proof of concept, high-resolution total X-ray scattering data of amorphous and crystalline calcium phosphates and amorphous calcium carbonate were collected for PDF analysis.

Single-wavelength X-ray anomalous diffraction (SAD) is a frequently employed technique to solve the phase problem in X-ray crystallography. The precision and accuracy of recovered anomalous differences are crucial for determining the correct phases. Continuous rotation (CR) and inverse-beam geometry (IBG) anomalous data collection methods have been performed on tetragonal lysozyme and monoclinic survivin crystals and analysis carried out of how correlated the pairs of Friedel's reflections are after scaling. A multivariate Bayesian model for estimating anomalous differences was tested, which takes into account the correlation between pairs of intensity observations and incorporates the a priori knowledge about the positivity of intensity. The CR and IBG data collection methods resulted in positive correlation between I(+) and I(−) observations, indicating that the anomalous difference dominates between these observations, rather than different levels of radiation damage. An alternative pairing method based on near simultaneously observed Bijvoet's pairs displayed lower correlation and it was unsuccessful for recovering useful anomalous differences when using the multivariate Bayesian model. In contrast, multivariate Bayesian treatment of Friedel's pairs improved the initial phasing of the two tested crystal systems and the two data collection methods.

A mysterious nocturnal animal was leaving its tracks on the delicate mirrors of the telescopes at the Smithsonian's Whipple Observatory in Arizona. With a little ingenuity and a live trap, the mystery was solved. The visitor proved to be a ringtail cat, a member of the raccoon family.

The post Astronomers solve mystery of dusty foot trails crossing telescope mirrors appeared first on Smithsonian Insider.

When two red panda babies are born in critical condition at Smithsonian’s National Zoo, caretakers make the crucial decision to raise them by hand.

The post Raising red pandas by hand at the National Zoo appeared first on Smithsonian Insider.

Ollie the bobcat, who escaped from her enclosure at the Smithsonian National Zoo, was found two days after her disappearance roaming near the zoo’s bird […]

The post Missing bobcat found on zoo property appeared first on Smithsonian Insider.

When Smithsonian Tropical Research Institute paleobotanist Carlos Jaramillo learned that Panama was expanding its canal in 2006 and blasting 100 million tons of rock to […]

The post Using Fossils in Panama to Model Future Climate Change appeared first on Smithsonian Insider.

Tuvan ensemble Alash demonstrates various traditional throat singing styles that they use in their music. Smithsonian Folkways Recordings video.

The post Alash demonstrates throat singing styles appeared first on Smithsonian Insider.

The storage and flux of terrestrial carbon (C) is one of the most uncertain components of the global C budget and detailed quantification of forest […]

The post Remote sensing of a Smithsonian forest with airborne LiDAR appeared first on Smithsonian Insider.

At the Smithsonian’s National Museum of Natural History, curator of arachnids and myriapods Hannah Wood has examined and analyzed hundreds of pelican spiders both in the field […]

The post Pelican spiders: Ancient assassins that eat their own kind appeared first on Smithsonian Insider.

Businesses are cutting back on hours to avoid having to provide health care coverage under the new Affordable Care Act.

Steve Julian: Business analyst Mark Lacter, who's affected here?

Mark Lacter: Thirty hours a week is the magic number for workers to be considered full time under the new law.  If a business has 50 or more full-time employees, health care coverage has to be provided.  Except that a lot business owners say that the additional cost is going to be a financial killer, so instead, some of them have been cutting back hours to below that 30-hour threshold.  More than 200,000 Californians are at risk of losing hours from the health care law - that according to one study.

Julian: What kinds of businesses are doing this?

Lacter: Restaurant chains have received much of the attention, but the city of Long Beach, as an example, is going to reduce hours for a couple of hundred of its workers.  And, last week came word that the L.A.-based clothing chain Forever 21 will cut some of its full-time employees to a maximum 29-and-a-half hours a week, and classify them as part time.  That touched off an outcry on the Internet - people were saying that Forever 21 was being unfair and greedy - though the company says that only a small number of employees are affected, and that its decision has nothing to do with the Affordable Care Act.  There's really no way to know - Forever 21 is a private company, which means it's not obligated to disclose a whole lot.  What we do know is that those people will be losing their health care coverage.

Julian: And, the ultimate impact on businesses and workers?

Lacter: Steve, you're looking at several years before the picture becomes clear.  Here in California, workers not eligible for health care through their employer can get their own individual coverage, and if their income levels are not over a certain amount, they'd be eligible for Medicaid.  And, let's not forget many businesses already provide coverage for their employees.  So, lots of rhetoric - but, not many conclusions to draw from, which does make you wonder why so many business owners are unwilling to at least give this thing a chance.  Just doesn't seem to be much generosity of spirit for their workers, not to mention any recognition that if people can go to a doctor instead of an emergency room we'd probably all be better off.

Julian: Health care is far from the only controversy for Forever 21, true?

Lacter: In some ways, it's one of the biggest Southern California success stories.  Don Chang emigrated here in 1981 from Korea at the age of 18, opened his first store in Highland Park three years later (it was called Fashion 21), and he never looked back.  Today, revenues are approaching $4 billion.  But, the guy must have some pretty hefty legal bills because his company has been accused of all kinds of workplace violations.  The lawsuits alleged that workers preparing items for the Forever 21 stores didn't receive overtime, that they didn't get required work breaks, that they received substandard wages, and that they worked in dirty and unsafe conditions - sweatshop conditions, essentially.

Julian: Are most of their claims settled out of court?  You don't hear much about them.

Lacter: They are, which means there's usually a minimal amount of media coverage.  If a privately held company decides to keep quiet by not releasing financial results or other operational information, there's not likely to be much of a story - unlike what happens with a company like Apple, which is always under scrutiny.  Sometimes, plaintiffs will try to organize class-action suits, but that's extremely tough when you're dealing with low-wage workers who are often very reluctant to get involved because of their legal status.  And, let's not forget that Forever 21 - like any low-cost retailer - is simply catering to the demand for cheap, stylish clothes that are made as quickly as possible.

Julian: I guess you can't make that happen when wages and benefits are appreciably higher than your competition.

Lacter: The next time you walk into a Forever 21 store and wonder how prices can be so reasonable, that's how.

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.

We've been reporting on the city of Los Angeles approving major developments without seismic studies attached.

Steve Julian: Business analyst Mark Lacter, why is this?

Mark Lacter: Steve, this is a real gotcha moment for the L.A. Planning Department, the City Council, and everyone else at City Hall who signed off on these projects.  The latest revelation, which was reported by the L.A. Times, shows that a planned 39-story residential tower in Century City is just 300 feet from the active Santa Monica fault.  And, we're only learning about this because the Metropolitan Transportation Authority did its own seismic testing near the site when it was looking for potential subway stops, and officials decided that it was too close to the fault.  This also comes after three large-scale projects in Hollywood were found to be located quite close to the active Hollywood fault.

Julian: The concern is that if any faults were to rupture, the foundation of a building could be split apart.

Lacter: Kind of an inconvenient truth both for the developers, who have millions of dollars riding on these projects, and for L.A. city officials who are betting on a future that will include many more high rises.  And, we should note that more than two-dozen high rises are either in the process of going up, or are at least on the drawing board.  In case you're wondering why there aren't regulations that monitor this sort of thing, the answer is that there are regulations.  California has a law that requires state geologists to map active earthquake faults, and then set zones on either side of the fault line.

Julian: Has the state done this?

Lacter: The state says it hasn't had the time nor the money to map areas within the city of L.A., though the faults have been known to be in the general vicinity of these projects - and so, you'd think the city would want them tested extensively.  Of course, that would mean more delays, which the developers wouldn't be happy with.

Julian: Of course, seismic studies are not always definitive.

Lacter: They're not - and it's possible that different geologists would come up with different findings.  But so far, most of the information seems to be coming from the developers, and you have to wonder whether it's a great idea to rely on folks who have a financial interest in a project to tell us what's safe and what isn't.  Probably not.

Julian: Your article in the new issue of Los Angeles Magazine raises a broader point about the city's business climate.

Lacter: Steve, for many years, L.A. has been branded as a terrible place to do business because of government interference, but that's largely a myth.  If anything, city officials have been too accommodating.  Frankly, the anti-business rap never made much sense when you consider the thousands of companies that start up here each year.  A study by the accounting firm PricewaterhouseCoopers ranks L.A. particularly high when it comes to ease of doing business, which runs counter to the conventional wisdom.

Julian: You're not saying it's truly easy, are you?

Lacter: Easy, no.  There certainly are plenty of reasons for business owners to pull out their hair.  And those hassles, along with an unemployment rate that remains quite high, has given developers and others the leverage to ask for various giveaways.  All they have to do is say that their projects will generate more jobs, and city officials tend to respond favorably - no matter how questionable those proposals might be.  And, by the way, job creation doesn't always determine economic growth, certainly not in the short term.

Julian: We all remember during the mayoral campaign, candidates were talking about how their policies would lead to lower unemployment...

Lacter: ...right, almost like they could pick up jobs at Ralphs.  Well, it doesn't work that way.  Thing is, the city of L.A. doesn't need to cut so many deals - the local economy is rich enough and broad enough to keep prospering.  Which is why city officials would be much better off laying off the incentives, and focusing on the basics - public safety, transportation, the parks, and libraries.  Do that right, and the business climate will take care of itself.

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.