One problem in unraveling the mystery of quasars is that many (perhaps most) quasar nuclei seem to be surrounded by a torus of obscuring dust that makes them difficult to study.

The post The origins of a torus in a galactic nucleus appeared first on Smithsonian Insider.

When most people look at a forest, they see walking trails, deer yards, or firewood for next winter. But scientists at the Harvard Forest and […]

The post Development will reduce carbon stored in forests, Smithsonian & Harvard scientists predict appeared first on Smithsonian Insider.

The National Museum of Natural History will construct a new dinosaur exhibition hall made possible by a $35 million donation from David H. Koch, executive vice president of Koch Industries and philanthropist.

The post $35-million donation will build new dinosaur hall at National Museum of Natural History appeared first on Smithsonian Insider.

The specimen’s skull measures 24 centimeters, roughly the size of a regulation NFL football. The shell which was recovered nearby – and is believed to belong to the same species – measures 172 centimeters, or about 5 feet 7 inches, long.

The post Giant prehistoric turtle from Colombia chomped everything in sight–including crocodiles! appeared first on Smithsonian Insider.

Smithsonian herpetologist George Zug answers a few questions about skinks....

The post Speaking of skinks: short limbed, long tailed & prehistoric appeared first on Smithsonian Insider.

The most peculiar feature of this new turtle is its extremely circular shell, about the size and shape of a big car tire.

The post Prehistoric turtle was size and shape of a big car tire appeared first on Smithsonian Insider.

A July 12 news alert from NASA indicates a X1.4 class solar flare erupted from the center of the Sun, peaking July 12 at 12:52 P.M.

The post Coronal mass ejection from July 12 solar flare headed toward Earth; minor geomagnetic storm activity predicted appeared first on Smithsonian Insider.

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.

The post Chandra X-ray Observatory shows Milky Way is surrounded by halo of hot gas appeared first on Smithsonian Insider.

What scientists found was that the domestic turkey that ends up on the dinner table exhibits less genetic variation than its ancestral wild counterparts, which were first domesticated in 800 B.C..

The post Today’s domestic turkeys are genetically distinct from wild ancestors appeared first on Smithsonian Insider.

The Smithsonian Astrophysical Observatory has been awarded a NASA project to build the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument. TEMPO will measure North American air pollution, from Mexico City to the Canadian tar/oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution.

The post NASA funds Smithsonian Astrophysical Observatory instrument to track North American air pollution appeared first on Smithsonian Insider.

Found in well preserved shale deposits the fossils are so detailed that scientists were able to determine they represent two previously unknown species.

The post Discovery of new prehistoric mosquitoes reveal these blood-suckers have changed little in 46 million years appeared first on Smithsonian Insider.

New data from NASA's Chandra X-ray Observatory suggest a highly distorted supernova remnant (shown here) may contain the most recent black hole formed in the Milky Way galaxy.

The post Highly distorted supernova remnant seen by Chandra X-ray Observatory appeared first on Smithsonian Insider.

Small migratory male birds that winter in a stressful environment age faster than those that winter in a high-quality habitat, according to research stemming from […]

The post Small migratory birds age faster in stressful places, study reveals appeared first on Smithsonian Insider.

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.

Rope, golf balls, sweat pants, bottles and aluminum cans are a few of the discarded items biologist Matt Klope says he has found inside the […]

The post Gray whale specimen an important addition to Natural History Museum collections appeared first on Smithsonian Insider.

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.

These striking images of six insect heads and mouthparts were drawn from fossils by Conrad Labandeira, Curator of Fossil Arthropods (insects and related animals) at […]

The post Prehistoric mouthparts appeared first on Smithsonian Insider.

Emmett Duffy, currently the Gluckman Professor of Marine Science at the College of William & Mary in Virginia, has been appointed director of the Smithsonian’s […]

The post Emmett Duffy named director of Smithsonian’s Tennenbaum Marine Observatories Network appeared first on Smithsonian Insider.

The Smithsonian’s National Air and Space Museum announced that it will receive a $6 million donation from the Thomas W. Haas Foundation to establish an […]

The post Air and Space Museum receives $6 million donation for Public Observatory Program appeared first on Smithsonian Insider.

Hopes are high for Comet ISON, which has the potential to become the most spectacular comet seen in years. ISON is speeding through the inner […]

The post Micro-Observatory catches comet ISON appeared first on Smithsonian Insider.

Termites and ants are not something you’re likely to pour into a cereal bowl for breakfast or munch with toast and tea, but your ancient […]

The post Termites for breakfast? Your ancestors might have! appeared first on Smithsonian Insider.

Fifteen years ago, NASA’s Chandra X-ray Observatory was launched into space aboard the Space Shuttle Columbia. Since its deployment on July 23, 1999, Chandra has […]

The post Chandra X-ray Observatory Celebrates 15th Anniversary appeared first on Smithsonian Insider.

New data from NASA’s Chandra X-ray Observatory offer a glimpse into the environment of a star before it exploded earlier this year, and insight into […]

The post Chandra Observatory searches for trigger of nearby supernova appeared first on Smithsonian Insider.

Before iPhones and laptops there were human computers, some of whom worked at the Harvard College Observatory. Women like Henrietta Swan Leavitt, Williamina Fleming, and […]

The post Volunteers needed to preserve astronomical history and promote discovery appeared first on Smithsonian Insider.

More than two million migrating raptors passed over Panama City on Sunday, Nov. 2, doubling the previous record of almost 900,000 tallied in a single […]

The post Panama shatters raptor migration record appeared first on Smithsonian Insider.

Point your smartphone at the skeleton of a vampire bat mounted in a museum case, wait a minute and you will see it wiggle, jump […]

The post New App adds Virtual Flesh to Victorian-era Bone exhibit appeared first on Smithsonian Insider.

Lurking on leaves in the tropical forests of Brazil microscopic mites in the family Cheyletidae are ambush predators. They wait quietly until another mite crawls […]

The post Newly named mites have thick skins to deter predators appeared first on Smithsonian Insider.

Tucked in the shadow of the towering Skylab exhibit at the Smithsonian’s National Air and Space Museum, there’s an inferno raging. Lucky for all of […]

The post Video from Solar Dynamics Observatory wows museum visitors appeared first on Smithsonian Insider.

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.

Ah, that new car smell. New plane smell is nice, too. Bright and shiny and fresh is good, right? Sure, unless it is a very […]

The post To Preserve Rare WWII bomber, Conservators Turn to Science appeared first on Smithsonian Insider.

From patterns etched into the skin of an ancient mummy to the colorful designs that adorn people today, tattoos are not just skin deep; they […]

The post Tattoos: Telling Stories in the Flesh. Q&A with Lars Krutak appeared first on Smithsonian Insider.

Researchers who examined thousands of migratory birds arriving in the United States from Central and South America have determined that three percent carry ticks species […]

The post Disease carrying ticks hitchhike into U.S. on migratory birds appeared first on Smithsonian Insider.

Now here is something to ruminate on. About 85 percent of the methane produced by a cow comes out of its mouth as burps. The […]

The post Monitoring methane? Now there is a better way to measure appeared first on Smithsonian Insider.

Pop quiz! Name the first five dinosaurs that come to mind. Chances are good that one you named was Tyrannosaurs rex, a popular favorite perhaps best […]

The post New horse-sized tyrannosaur with big brain reveals how “T. rex” became top predator appeared first on Smithsonian Insider.

Space: the final frontier. These are the voyages of the Starship Enterprise…and you know the rest, probably even if you’re not a huge fan of […]

The post Five things only a conservator would know about the USS Enterprise appeared first on Smithsonian Insider.

In 1935, 101 cane toads from Hawaii were set loose in Australia to help control beetles that were decimating the Australian sugar crop. But instead […]

The post Discovery: Australia’s invasive cane toads modify their bodies to conquer new territory faster appeared first on Smithsonian Insider.

Four years after conservationists relocated 570 desert tortoises (Gopherus agassizii) in California from a threatened habitat to a new nearby location, the tortoises outwardly appeared […]

The post Smithsonian Study shows relocated desert tortoises reproduce at lower rate appeared first on Smithsonian Insider.

With its homely featherless head, undertaker’s charcoal coloring and association with death and decay, the turkey vulture (Cathartes aura) tops few lists as a favorite […]

The post Scientists in awe of huge olfactory bulb found in turkey vulture brain appeared first on Smithsonian Insider.

A new study from the Smithsonian Conservation Biology Institute (SCBI) is helping make headway in an area of animal management that has historically proven challenging: […]

The post Early indicator of cheetah pregnancy identified appeared first on Smithsonian Insider.

When “2001: A Space Odyssey” premiered April 2, 1968 at Washington, D.C.’s Uptown Theater—not far from the Smithsonian’s National Air and Space Museum—not everyone was […]

The post The real history behind science fiction’s ‘2001: A Space Odyssey’ appeared first on Smithsonian Insider.

People often use the words turtle and tortoise interchangeably, but these reptiles have distinct differences: Turtle shells are typically more flattened and not as deeply […]

The post Five fun turtle and tortoise facts from the Smithsonian’s National Zoo 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.

l-Hydroxyproline (l-Hyp) is a nonstandard amino acid that is present in certain proteins, in some antibiotics and in the cell-wall components of plants. l-Hyp is the product of the post-translational modification of protein prolines by prolyl hydroxylase enzymes, and the isomers trans-3-hydroxy-l-proline (T3LHyp) and trans-4-hydroxy-l-proline (T4LHyp) are major components of mammalian collagen. T4LHyp follows two distinct degradation pathways in bacteria and mammals, while T3LHyp is metabolized by a two-step metabolic pathway that is conserved in bacteria and mammals, which involves a T3LHyp dehydratase and a Δ1-pyrroline-2-carboxylate (Pyr2C) reductase. In order to shed light on the structure and catalysis of the enzyme involved in the second step of the T3LHyp degradation pathway, the crystal structure of Pyr2C reductase from the archaeon Thermococcus litoralis DSM 5473 complexed with NADH and l-proline is presented. The model allows the mapping of the residues involved in cofactor and product binding and represents a valid model for rationalizing the catalysis of Pyr2C reductases.

The bond-valence method has been used for valence calculations of FeMo/V cofactors in FeMo/V proteins using 51 crystallographic data sets of FeMo/V proteins from the Protein Data Bank. The calculations show molybdenum(III) to be present in MoFe7S9C(Cys)(HHis)[R-(H)homocit] (where H4homocit is homocitric acid, HCys is cysteine and HHis is histidine) in FeMo cofactors, while vanadium(III) with a more reduced iron complement is obtained for FeV cofactors. Using an error analysis of the calculated valences, it was found that in FeMo cofactors Fe1, Fe6 and Fe7 can be unambiguously assigned as iron(III), while Fe2, Fe3, Fe4 and Fe5 show different degrees of mixed valences for the individual Fe atoms. For the FeV cofactors in PDB entry 5n6y, Fe4, Fe5 and Fe6 correspond to iron(II), iron(II) and iron(III), respectively, while Fe1, Fe2, Fe3 and Fe7 exhibit strongly mixed valences. Special situations such as CO-bound and selenium-substituted FeMo cofactors and O(N)H-bridged FeV cofactors are also discussed and suggest rearrangement of the electron configuration on the substitution of the bridging S atoms.

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.

Photographs, by virtue of their static nature, not only allow us to look back to a fixed point in time, but also give us a […]

The post Book Review: Double Exposure: photos of African American History & Culture appeared first on Smithsonian Insider.

Kasun Buddika, Ishara S. Ariyapala, Mary A. Hazuga, Derek Riffert, and Nicholas S. Sokol

Stressed cells downregulate translation initiation and assemble membrane-less foci termed stress granules (SGs). Extensively characterized in cultured cells, the existence of such structures in stressed adult stem cell pools remain poorly characterized. Here we report that Drosophila orthologs of mammalian SG components AGO1, ATX2, CAPRIN, eIF4E, FMRP, G3BP, LIN-28, PABP, and TIAR are enriched in adult intestinal progenitor cells where they accumulate in small cytoplasmic messenger ribonucleoprotein complexes (mRNPs). Treatment with sodium arsenite or rapamycin reorganized these mRNPs into large cytoplasmic granules. Formation of these intestinal progenitor stress granules (IPSGs) depended on polysome disassembly, led to translational downregulation, and was reversible. While canonical SG nucleators ATX2 and G3BP were sufficient for IPSG formation in the absence of stress, neither of them, nor TIAR, either individually or collectively, were required for stress-induced IPSG formation. This work therefore finds that IPSGs do not assemble via a canonical mechanism, raising the possibility that other stem cell populations employ a similar stress-response mechanism.

Kristina Drizyte-Miller, Jing Chen, Hong Cao, Micah B. Schott, and Mark A. McNiven

Epithelial cells such as liver-resident hepatocytes rely heavily on the Rab family of small GTPases to perform membrane trafficking events that dictate cell physiology and metabolism. Not surprisingly, disruption of several Rabs can manifest in metabolic diseases or cancer. Rab32 is expressed in many secretory epithelial cells but its role in cellular metabolism is virtually unknown. In this study, we find that Rab32 associates with lysosomes and regulates proliferation and cell size of Hep3B hepatoma and HeLa cells. Specifically, we identify that Rab32 supports mTORC1 signaling under basal and amino acid stimulated conditions. Consistent with inhibited mTORC1, an increase in nuclear TFEB localization and lysosome biogenesis is also observed in Rab32-depleted cells. Finally, we find that Rab32 interacts with mTOR kinase and that loss of Rab32 reduces the association of mTOR and mTORC1 pathway proteins with lysosomes, suggesting that Rab32 regulates lysosomal mTOR trafficking. In summary, these findings suggest that Rab32 functions as a novel regulator of cellular metabolism through supporting mTORC1 signaling.

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.

Javad Fahanik-babaei, Bahareh Rezaee, Maryam Nazari, Nihad Torabi, Reza Saghiri, Remy Sauve, and Afsaneh Eliassi

We have determined the electropharmacological properties of a new potassium channel from brain mitochondrial membrane by planar lipid bilayer method. Our results showed the presence of a channel with a conductance of 150 pS at potentials between 0 and –60 mV in 200 cis/50 trans mM KCl solutions.

The channel was voltage-independent, with an open probability value ~0.6 at different voltages. ATP did not affect current amplitude and Po at positive and negative voltages. Notably, adding iberiotoxin, charybdotoxin, lidocaine, and margatoxin had no effect on the channel behavior. Similarly, no changes were observed by decreasing the cis-pH to 6. Interestingly, the channel was inhibited by adding sodium in a dose dependent manner. Our results also indicated a significant increase in mitochondrial complex IV activity and membrane potential and decrease in complex I activity and mitochondrial ROS production in the presence of sodium ions.

We propose that inhibition of mitochondrial K⁺ transport by Na ions on K⁺ channel opening may be important for cell protection and ATP synthesis.