Astronomers have found strong evidence that a massive black hole is being ejected from its host galaxy at a speed of several million miles per hour.

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The dying star, which lit the galactic scene, is the most distant stellar explosion of its kind ever studied.

The post Dying star illuminates distant galaxy, lifting veil of interstellar darkness for astronomers appeared first on Smithsonian Insider.

Hew research by astronomers at the Harvard-Smithsonian Center for Astrophysics shows that planets still can form in the cosmic maelstrom of Milky Way's center.

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stronomers have used NASA's Chandra X-ray Observatory to find evidence our Milky Way Galaxy is embedded in an enormous halo of hot gas that extends for hundreds of thousands of light years.

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Astronomers have discovered that one well-known elliptical galaxy has a split personality. Centaurus A is hiding a gassy spiral in its center.

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One of the closest galaxies to the Milky Way almost got away with theft....

The post Galactic thief: “I would have gotten away with it but for those meddling astronomers!” appeared first on Smithsonian Insider.

This image shows the active star-forming galaxy M82 in three wavelengths: UV (blue), near-infrared (green) and far-infrared (red). New research indicates that even in the […]

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Frontispiece illustration of “flies” from the 1882 book American game fishes, their habits, habitat, and peculiarities; how, when, and where to angle for them, featuring […]

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The uplift of the Isthmus of Panama 2.6 million years ago formed a land-bridge that has long thought to be the crucial step in the […]

The post Alligator relatives crossed ancient seaway appeared first on Smithsonian Insider.

Spiral galaxies are some of the most beautiful and photogenic residents of the universe. Our own Milky Way is a spiral. Our solar system and […]

The post Powerful computer simulations show how spiral galaxies get their arms appeared first on Smithsonian Insider.

This composite image of a galaxy illustrates how the intense gravity of a super massive black hole can be tapped to generate immense power. The image […]

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Using data from NASA’s Chandra X-ray Observatory, astronomers have discovered an unprecedented bonanza of black holes in the Andromeda Galaxy, one of the nearest galaxies […]

The post Chandra X-ray Observatory turns up black hole bonanza in galaxy next door appeared first on Smithsonian Insider.

Fond of a range of marine and freshwater vegetation such as turtle grass and eelgrass, the Florida manatee spends most of its waking hours grazing […]

The post Algae bloom toxins may make Florida’s manatees and sea turtles susceptible to deadly accidents appeared first on Smithsonian Insider.

An international team of astronomers has discovered the first Earth-mass planet that transits, or crosses in front of, its host star. KOI-314c is the lightest […]

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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.

The galaxy known as M87 has a fastball that would be the envy of any baseball pitcher. It has thrown an entire star cluster toward […]

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Astronomers announced today that they have discovered a new type of planet – a rocky world weighing 17 times as much as Earth. Theorists believed […]

The post Astronomers find new type of planet: The “Mega-Earth” appeared first on Smithsonian Insider.

The world of astronomy has changed. An astronomer used to have to travel to a remote location and endure long, cold nights, patiently guiding a […]

The post Mining astronomical archives yields haul of “red nugget” galaxies appeared first on Smithsonian Insider.

In the United States, natural-gas production from shale rock has increased by more than 700 percent since 2007. Yet scientists still do not fully understand […]

The post Biological fallout of shale-gas production still largely unknown appeared first on Smithsonian Insider.

In theory, crabs of the species Planes major should stay true to their mates for life. Heterosexual pairs of these small crustaceans live on loggerhead […]

The post Faithful crabs engage in risky behavior when opportunity arises appeared first on Smithsonian Insider.

The challenges of conceiving only get greater as we get older. But if you have some of the most prized genes within your entire species, […]

The post High hopes for 60 year-old crocodile to become mother again appeared first on Smithsonian Insider.

For the first time, astronomers have detected the presence of complex organic molecules, the building blocks of life, in a protoplanetary disk surrounding a young […]

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A case of mistaken identity turned out to be the key for proving that a prehistoric aquatic reptile did not lay eggs, but rather gave […]

The post Fossil shows Prehistoric Reptile Gave Birth in Open Ocean appeared first on Smithsonian Insider.

Batteries power virtually every aspect of modern life. So small, so portable, and so easy to forget—but how many times have you simply started your […]

The post Unplugged: 5 batteries that gave the world a jolt appeared first on Smithsonian Insider.

The center of our Milky Way galaxy is a mysterious place. Not only is it thousands of light-years away, it’s also cloaked in so much […]

The post RADIO TELESCOPES COULD SPOT STARS HIDDEN IN THE GALACTIC CENTER appeared first on Smithsonian Insider.

When astronomers study protoplanetary disks of gas and dust that surround young stars, they sometimes spot a dark gap like the Cassini division in Saturn’s […]

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In many ways stars are like living beings. They’re born; they live; they die. And they even have a heartbeat. Using a novel technique, astronomers […]

The post DISCOVERY MEASURES “HEARTBEATS” OF A DISTANT GALAXY’S STARS appeared first on Smithsonian Insider.

In April 2015, after traveling for about half the age of the universe, a flood of powerful gamma rays from a distant galaxy slammed into […]

The post VERITAS Detects Gamma Rays from Galaxy Halfway Across the Visible Universe appeared first on Smithsonian Insider.

As the Zika virus is rapidly taking hold around the world, health officials are racing to find its cause and prevent further spread of the […]

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Keith Gagnon, a 9-year-old fascinated by birds, talks about the importance of bird conservation and why birds really matter. Step outside your house in the […]

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The Smithsonian’s National Portrait Gallery celebrates the accomplishments of astronaut and Senator John Glenn (1921-2016) with a watercolor and graphite portrait by Henry C. Caselli […]

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Every few thousand years, an unlucky star wanders too close to the black hole at the center of the Milky Way. The black hole’s powerful […]

The post Our Galaxy’s Black Hole is Spewing Planet-size “Spitballs” appeared first on Smithsonian Insider.

The 11 farthest known stars in our galaxy are located about 300,000 light-years from Earth, well outside the Milky Way’s spiral disk. New research by […]

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Fast radio bursts (FRBs) are brief spurts of radio emission, lasting just one-thousandth of a second, whose origins are mysterious. Fewer than two dozen have […]

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The center of our Galaxy has been intensely studied for many years, but it still harbors surprises for scientists. A snake-like structure lurking near our […]

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In 1854, a curious-looking spider was found preserved in 50 million-year-old amber. With an elongated neck-like structure and long mouthparts that protruded from the “head” […]

The post These newly discovered pelican spiders will make you want to visit Madagascar appeared first on Smithsonian Insider.

“Somber” is the adjective Smithsonian beetle expert Terry Erwin uses to describe the insects he collects on the forest floor in Peru and Ecuador. “They […]

The post Meet the newest New World canopy beetle species. ‘Gazillions’ await discovery. appeared first on Smithsonian Insider.

Warner’s narrative covers the major natural sweeteners, including sugar, molasses from cane, beet sugar, corn syrup, honey and maple, as well as artificial sweeteners such as saccharin, cyclamate, aspartame and sucralose.

The post New Book: “Sweet Stuff: An American History of Sweeteners from Sugar to Sucralose” appeared first on Smithsonian Insider.

Yinlong Song, Yikan Zhang, Ying Pan, Jianfeng He, Yan Wang, Wei Chen, Jing Guo, Haiteng Deng, Yi Xue, Xianyang Fang, and Xin Liang

Microtubules dynamics is regulated by the plus end-tracking proteins (+TIPs) in cells. End binding protein 1 (EB1) acts as a master regulator in +TIPs networks by targeting microtubule growing ends and recruiting other factors. However, the molecular mechanism of how EB1 binds to microtubule ends with a high affinity remains to be an open question. Using single-molecule imaging, we show that the end-binding kinetics of EB1 changes along with the polymerizing and hydrolysis rate of tubulin dimers, confirming the binding of EB1 to GTP/GDP-Pi tubulin at microtubule growing ends. The affinity of wild-type EB1 to these sites is higher than monomeric EB1 mutants, suggesting that two CH domains in the dimer contribute to the end-binding. Introducing phosphomimicking mutations into the linker domain of EB1 weakens the end-binding affinity and confers a more curved conformation to EB1 dimer without compromising dimerization, suggesting that the overall architecture of EB1 is important for the end-binding affinity. Taken together, our results provide insights into understanding how the high-affinity end-binding of EB1 can be achieved and how this activity may be regulated in cells.

Benjamin Ziman, Peter Karabinis, Paul Barghouth, and Nestor J. Oviedo

Nutrient availability upon feeding leads to an increase in body size in the planarian Schmidtea mediterranea. However, it remains unclear how food consumption integrates with cell division at the organismal level. Here we show that Sirtuins is evolutionarily conserved in planarians and specifically demonstrate that Sirtuin-1 (Smed-Sirt-1) regulates organismal growth by impairing both feeding behavior and intestinal morphology. Disruption of Smed-Sirt-1 with either RNAi or pharmacological treatment leads to reduced animal growth. Conversely, enhancement of Smed-Sirt-1 with resveratrol accelerates growth. Differences in growth rates were associated with changes in the amount of time to locate food and overall consumption. Furthermore, Smed-Sirt-1(RNAi) animals displayed reduced cell death and increased stem cell proliferation accompanied by impaired expression of intestinal lineage progenitors and reduced branching of the gut. Altogether, our findings indicate Sirtuin-1 is a crucial metabolic hub capable of controlling animal behavior, tissue renewal and morphogenesis of the adult intestine.

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.

Laurence Haren, Dorian Farache, Laurent Emorine, and Andreas Merdes

-tubulin is a major protein involved in the nucleation of microtubules in all eukaryotes. It forms two different complexes with proteins of the GCP family (gamma-tubulin complex proteins): -tubulin small complexes (TuSCs), containing -tubulin and GCPs 2 and 3, and -tubulin ring complexes (TuRCs), containing multiple TuSCs, in addition to GCPs 4, 5, and 6. Whereas the structure and assembly properties of TuSCs have been intensively studied, little is known about the assembly of TuRCs, and about the specific roles of GCPs 4, 5, and 6. Here, we demonstrate that two copies of GCP4 and one copy each of GCP5 and GCP6 form a salt-resistant sub-complex within the TuRC that assembles independently of the presence of TuSCs. Incubation of this sub-complex with cytoplasmic extracts containing TuSCs leads to the reconstitution of TuRCs that are competent to nucleate microtubules. In addition, we investigate sequence extensions and insertions that are specifically found at the amino-terminus of GCP6, and between the GCP6 grip1 and grip2 motifs, and we demonstrate that these are involved in the assembly or stabilization of the TuRC.

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.

Ganlu Deng, Yihong Chen, Cao Guo, Ling Yin, Ying Han, Yiyi Li, Yaojie Fu, Changjing Cai, Hong Shen, and Shan Zeng

Epithelial-mesenchymal transition (EMT) is a crucial process for cancer cells to acquire metastatic potential, which primarily causes death in gastric cancer (GC) patients. Bone morphogenetic protein 4 (BMP4) is a member of the TGF-β family that plays an indispensable role in human cancers. However, little is known about its roles in GC metastasis. In this study, BMP4 was found to be frequently overexpressed in GC tissues and was correlated with patient's poor prognosis. BMP4 was upregulated in GC cell lines and promoted EMT and metastasis of GC cells both in vitro and in vivo, while knockdown of BMP4 significantly inhibited EMT and metastasis of GC cells. Meanwhile, the inhibitor of DNA binding 1 (Id1) was identified as a downstream target of BMP4 by PCR arrays and upregulated via Smad1/5/8 phosphorylation. Id1 knockdown attenuated BMP4-induced EMT and invasion in GC cells. Moreover, Id1 overexpression in BMP4 knockdown cells restored the promotion of EMT and cell invasion. In summary, BMP4 induced EMT to promote GC metastasis by upregulating Id1 expression. Antagonizing BMP4 may be a potential therapeutic strategy in GC metastasis.

Formed some 250,000 years ago when the Nile River pushed through a low channel near Wadi Tushka, it flooded the eastern Sahara, creating a lake that at its highest level covered more than 42,000 square miles.

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During a press conference Friday, July 22 at the Smithsonian's National Air and Space Museum, NASA announced that Gale Crater will be the landing site for the Mars Science Laboratory. Scheduled to launch in late 2011 and arrive at Mars in August 2012, the Mars Science Laboratory is a rover that will assess the planet’s “habitability”—if it ever was, or is today, an environment able to support microbial life.

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According to the weekly report of the Smithsonian’s Global Volcanism Program, gas-and-ash plumes rose nearly one mile above the crater of Mexico’s Popocatépetl volcano from […]

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Great white sharks, killer whales, sea lions, even polar bears—the ocean is full of giant predators. But one of the ocean’s worst enemies is not […]

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In the battle against invasive species, giant commercial ships are on the front lines. But even when they follow the rules, one of their best […]

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Monday, Aug. 21 was an unusual day across North America. Early in the morning, families, colleagues and tourists were searching for special solar glasses with […]

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